The thousands who thronged the streets of Washington, and millions more who tuned in across America and overseas have witnessed an historic moment. The first African-American US president, sworn in, promising a new era of American leadership and responsibility. The celebrations will continue through the night; the Obamas have 10 inaugural balls to attend for a start. Our live coverage ends now, however, but you can keep up with all the latest developments here.
1659 A symbolic moment, as the Obama family emerges from the White House for the first time. The president's daughters Malia and Sasha, dressed in blue and red, skip along excitedly, holding their parents' hands as they head to the viewing platform.
Christina, Oregon, US:
Many of us with "high expectations" are simply grateful that he will be leading us through this storm. We aren't expecting him to miraculously clear the skies. More of your comments.
Nadia, Cairo, Egypt:
I really liked Obama's speech, especially his clear denunciation of the Bush era. But I also felt a little scared as I watched him. He is too idealistic and internationalist for the Americans. More of your comments.
1646 Light is starting to fade in Washington. Having entered the White House as president for the first time, Mr Obama is going to be watching the end of the parade in the dark at this rate. Already the crowds lining the route from the Capitol are beginning to thin out in places; It has been a historic day for them, but it has also been a long and cold one.
David Biespiel in The Arena:
I write this as a Texan who grew up in a racially polarized South, and I write not as a Child of the Sixties but as a child during the 60s. Upon taking his oath, President Obama did more than break a vicious racial barrier in American history, he became the physical embodiment of the ideal of American unification. Read more on The Arena, Politco.com.
1642 The BBC's Rajesh Mirchandani on Pennsylvania Avenue: There are now more police officers lining the parade route than spectators. They clearly got what they came for: a glimpse of President Obama. Now they want to get warm.
RM, New Jersey, US:
The fact that any minority can achieve anything in our country makes me proud, but let him accomplish something first and we will celebrate afterwards. More of your comments.
1638 The Obamas are clearly enjoying this moment; both are beaming as they wave to the crowds. As the pair near the White House, they get back into their limousine as they travel round to the south side of the building. The Bidens are still on their feet, passing the viewing platform from where the presidential party will watch the parade.
Suraj Ajadi, Israel:
No doubt, this is the beginning of a new dawn. I see the commitment and sincerity of hope in this man. This revolution is going to lead to the emergence of many 'Obamas' in many parts of the world. More of your comments.
"We reject as false the choice between our safety and our ideals." Outside the limo. Talking the talk and walking the walk. Read aprillwrites' tweets.
1630 The first couple are out of the car once again as the convoy nears the White House, their home for the next four years. As the day's dramatic events have unfolded, behind the scenes there has been frantic activity at the presidential residence - moving the Bushes' possessions out, and the Obamas' in.
1629 The BBC's Rajesh Mirchandani on Pennsylvania Avenue: Sixteen police and secret service vehicles follow the presidential limo. It's moving at a snail's pace. The crowd went wild for the 90 seconds Obama took to pass. Then, as soon as the limo was gone, so were the crowds. They virtually raced for the exits. Poor Joe Biden - he walked past us here at Freedom Plaza, but didn't get nearly as big a cheer.
Amused by Canadian Embassy revelers in furs & Chanel mixing it up w/ brothers in the street. Read organicmania's tweets.
Alex Koppelman in War Room:
What happened here Tuesday wasn't just the transfer of power from one president to another. From the grounds of the Capitol, not far from the podium where Barack Obama took the oath of office, it seemed more like a whole new generation, a new era. Read more on War Room, Salon.com.
V Ashkenazy, Pura, Switzerland:
I didn't watch the inauguration as I saw no point in watching the end of the US as a beacon of individual rights. Obama is going to put the final nail in the free enterprise coffin. More of your comments.
Biden just passed us, also on foot. Well 10 hours outside worth it. Read yumke's tweets.
Ted, Moscow, Russia:
I am in Moscow and I am excited that Barack Obama has become president. Barack Obama is the world's president. More of your comments.
1614 The Obamas and Bidens return to their vehicles, much to the relief of the agents walking alongside. The BBC's Matt Frei says rarely has a president in office been greeted by such a wave of goodwill - or needed such support to solve the country's problems.
1610 The noise is deafening as the Obamas make their way along the route, past Washington landmarks and crowds 10-deep. On either side, people scream, wave and take pictures. Behind, the vice president and his wife have also stepped out of their vehicle and savour the moment.
Hugo, Andrea and Tim, Cadíz, Spain:
We have just watched his speech and we think that it's not just false promises. The world hopes, Cadíz expects. More of your comments.
B, Pennsylvania, US:
I think President Obama brings freshness to the whole political spectrum. I wish him luck on the next phase of his journey. I hope he delivers on his campaign promises. More of your comments.
1608 The BBC's Matt Frei: This is the happiest that I have seen him all day. He looked slightly sombre at his lunch on Capitol Hill.
1605 The motorcade stops and President Obama emerges from his limousine to rapturous applause. He is joined by his wife and the pair wave to the crowds, wearing wide smiles.
Paul in Power Line:
President Obama's inaugural address was, I think, quite good for what it was… The speech was classic Obama - the kind of fine-sounding, frivolous fare in which the idea that we face specific trade-offs is dismissed as cynicism, even as we're told in the most general way of the need for sacrifice... If Obama believed his own rhetoric, it would be scary. But like most of his predecessors, he comes to office believing almost exclusively in himself - a somewhat less frightening proposition. Read more on Power Line.
Applause ripples down the parade route ahead of the presidential motorcade. The crowds are hoping to see President Obama's first walkabout, but the secret service may have something to say about that. The pace of the convoy is slow enough for all to get a good look at the commander-in-chief, though.
1546 As the parade crawls down Pennsylvania Avenue, there is news from Washington Hospital Center; Senator Kennedy is awake and doctors are assessing him, the Associated Press reports.
David Freddoso in The Corner:
Just based on the 500 to 600 private jets that came to today's event, you can bet that the carbon footprint for this inauguration more than makes up for the conservation efforts by Democrats on Capitol Hill - probably for years to come. But throw in all of the buses that are idling along Independence Avenue today, and we might actually have warmer weather by the end of the week. Read more on The Corner on National Review Online.
ZC, Tao Payoh, Singapore:
Much will be expected from President Obama, especially with the difficult times ahead. From his inauguration speech, he is realistic and down to earth. More of your comments.
1542 BBC North America editor Justin Webb:
By the way, a large chunk of the speech was borrowed from Thomas Paine... including the most moving passages at the end. Should he have told us?
Juliet Eilperin on Washingtonpost.com:
In what may well be the furthest-flung celebration of Barack Obama's inauguration, scientists aboard the US research vessel Laurence M Gould held a commemoration 10,000 miles from Washington DC off Antarctica. The researchers, who are spending three days at sea examining signs of climate change, decided to call the temporary study area they have established Ocean Station Obama. Read more on washingtonpost.com.
1539 The parade finally sets off. More than 13,000 participants from all 50 US states will travel the 1.5-mile route, lined with people, many of whom have waited since the early hours of the morning. At the head of the parade, a phalanx of motorcycles with outriders, lights gleaming leads the way.
1538 BBC North America editor Justin Webb:
Watching the pictures of the new president saying goodbye to the old - the warmth and respect as the families stood next to the waiting chopper - it occurred to me that one thing is certain: there will be no vendetta, deserved or not. There will be no prosecutions. It's over.
Abay, Göteborg, Sweden:
I am sure President Obama will bring a real change and peace, freedom and prosperity to poor and rich nations. More of your comments.
1529 The Obamas step into an armoured black limousine, nicknamed the Beast, with the number plate "USA1". It moves off at walking pace, flanked on either side by secret service agents, before coming to a halt ahead of the start of the inaugural parade. The president is expected to walk some of the way along the route.
Tom Bevan on the Real Clear Politics blog:
The speech was quite good and well delivered. But it was not "great" - in the historical scope of inaugural addresses - and nothing in it struck me as particularly historic or memorable. There was no signature line, no mantra for the ages, and no powerful theme that will affix this speech in the public consciousness for years to come. Read more on the Real Clear Politics blog.
1520 President Obama and the first lady emerge from the Capitol, and walk down the East steps with the Bidens. They pause at the bottom to review troops parading past.
The World Newser:
Chief Justice John Roberts is a man who has made very few public missteps in his life - but he appears to have made one when swearing in Barack Obama. Roberts slightly flubbed the oath, which then tripped up Obama. Read more on the World Newser, abcnews.com.
1517 Robert Byrd's office says the senator is "fine", according to Reuters.
Karin, Vienna, Austria:
It is the most uplifting event in a long time, bringing hope and new possibilities for peace, the global environment, justice, and sustainable recovery. More of your comments.
1514 The BBC's Richard Lister says the tone of President Obama's remarks about Senator Kennedy has given everybody cause for concern. There has been no word yet on the senator's condition. Senator Kennedy was diagnosed last year as having a cancerous brain tumour.
1510 Rajesh Mirchandani on Pennsylvania Avenue: Huge numbers of police from forces around the US lining the parade route. People in tall buildings around on balconies and roofs. Police officers also discreetly on roofs.
Kelly Anderson, Utah, US:
Best of luck and I'm optimistic, but as things go it won't be long before Obama is bogged down in the business-as-usual. I'm keeping my expectations realistic. More of your comments.
1504 Reports suggest that Senator Kennedy suffered a seizure at the inaugural lunch. CNN reports that the veteran US senator, Robert Byrd, also had a medical issue requiring attention at the meal.
William, Cambridge, UK:
Obama won't be perfect but if he's honest and tries his hardest then that's better than what we've received for decades. More of your comments.
1458 To the applause of senior members of Congress, Mr Obama ends his speech, saying: "Thank you all for this great honour and I look forward to working with you in the years to come."
1457 The BBC's Jon Leyne in Tehran: I think the government here is very cautious, very divided, and doesn't really know what to do about an American president who, for the moment at least, is extremely popular around the world. So they're really sitting on their hands, waiting to see how to play it.
1455 "The depth of the moment is expressed by the people beyond these halls," says President Obama. "What is happening today is not about me, it is about the American people."
1452 President Obama begins a speech to diners, saying first that his prayers are with Ted Kennedy and his family.
1451 NBC reports that the person who collapsed at the luncheon was Senator Ted Kennedy. The network says he was taken from the Statuary Hall on a stretcher.
1448 The Obamas and Bidens, still at their lunch table, are presented with framed photographs of the inauguration ceremony, and then accept gifts of a pair of crystal bowls.
Geraldine Cooper, Dubai, UAE:
I am filled with admiration for Obama. I can't help but feel that the media should stop focussing on the "Afro-American" thing and concentrate on his politics. More of your comments.
1444 Paramedics were called at 1435 to the Statuary Hall luncheon, apparently to attend to a guest who collapsed, according to CNN.
1441 Two lines of US Marine guards form on the East steps of the Capitol. President Obama and Vice President Biden will shortly exit here on foot and review the troops.
Michelle Malkin's blog:
About that race-based benediction... Lowery got big cheers when he weaved in a weird prayer rap expressing his hope for a future in which the "brown would stick around", the "yellow would be mellow", the "red man would get ahead, man", and the "white would embrace the right"... What would Obama's grandparents and mother have to say? Read more Michelle Malkin.
1430 The parade that will follow Barack Obama down Pennsylvania Avenue is beginning to form. Thousands of people are being brought into line, ready for the next stage of the inaugural celebrations.
Gabriel Winant in War Room:
When the crowd on the Mall turned and waved at the chopper carrying the Bushes to Andrews Air Force Base, one got the sense that it wasn't the fondest farewell... If you were hoping for an iconic, Nixon-style goodbye gesture from the most reviled president since Watergate, you were probably disappointed. Still, it's fun to wonder: when he gets in bed in Crawford tonight, what will Bush wish he could have said or done, but for the bounds of propriety? Read more on War Room, Salon.com.
1428 The BBC's Jon Leyne, in Tehran, says there is an awful lot of hope in Iran for the new US president, but he cautions that there is still a great deal bitterness over America's strong support of Israel.
1426 The BBC's Kevin Connolly at the Capitol: An hour after Obama's speech ended, tens of thousands of temporary seats erected on the Capitol's imposing steps and sweeping lawns are more or less empty. But hundreds of visitors remain, taking photographs of each other posing in front of the inaugural podium and occasionally dancing with strangers to the music carried on the icy air by the public address system.
Keith Hall, Helsinki, Finland:
It's been a long time coming and today history has been made. America has the best possible president for these turbulent times. More of your comments.
Melanie, Bangalore, India:
I was extremely thrilled with Obama's victory but am feeling a sense of disappointment now - over the people that he selected to aid his administration when he spoke so much of "change".
More of your comments.
1421 Alex Jakarna of BBC World Service's Africa Have Your Say programme: We have had callers, texters and listeners from all over the place - Ghana, Sierra Leone, Kenya and Sudan - and in each of these places there were parties going on. In some of them we could hear the thumping of loudspeakers in the background. In Sierra Leone they took over an entire cinema and lots of people were in there, in Khartoum one of the residents was on his roof giving us a panoramic view, describing lots of people on the streets.
1416 At Lafayette Square, dignitaries are arriving to take their seats. They will watch the inaugural parade, headed by President Obama, arrive at the square, travelling from the Capitol, down Pennsylvania Avenue to the street's most famous address, number 1600; the White House.
L Bruce, Alaska, US:
Obama hasn't done anything yet. I'm not swayed by his words. I'm waiting for action. And while I am pleased to see Obama has become a role model indemnifying black America, it's not about race. More of your comments.
1409 Mr Bush's aircraft lifts off and makes a final circle over Washington DC before heading on its course. The Bushes are bound for Midland, Texas, where they will attend a homecoming celebration and then head to their ranch in Crawford for their first night as private citizens again.
What a speech!! Speaking as a citizen of the world that was exactly what I wanted to hear from an American President. Read MayorOfLondon's tweets.
guy in line at the hot dog stand told me to get out of his ear with my phone call. guess things ARE back to normal. Read dannythedemon's tweets.
1356 Former President Bush boards an aircraft which will take him and his wife from Andrews Air Force base back to their Texas home.
1355 The BBC's Rajesh Mirchandani on Pennsylvania Avenue: Small groups of people waiting for the parade are holding impromptu dance-offs, mainly to keep warm. Their choreography is spontaneous and infectious. Music is being piped through big speakers, but it's a very small playlist on an often-repeated loop! Even the most ardent are getting a little impatient.
1348 The BBC's Will Grant in Caracas, Venezuela: State TV didn't cover the event. Nevertheless there is keen interest here and many people here are looking to see what will develop with an Obama presidency… There's a sense of wait and see here, driven both by President Chavez and the people of Venezuela.
1346 In Birmingham, Alabama, the heart of the civil rights protests in the 1960s, some of those who watched the inauguration on television have told the BBC it was a sight they thought they'd never see. One person said: "I was a foot soldier, and I went on the marches - all the segregation, and riding the buses in the back and drinking out of coloured fountains, and using the coloured bathrooms - all of this is just so great."
1345 The BBC's Michael Voss in Havana, Cuba: It didn't make the headlines on lunchtime news... they showed black and white footage of Martin Luther King in Washington. Fidel Castro has called President Obama a decent man, his brother president Raul Castro called him an honest man, so I think there is a lot of hope here that there will be change.
1342 The BBC's Laura Shields at a Democrats Abroad party in Brussels: The reaction here is very excited, the atmosphere is very convivial, there's a mixture of Europeans and Americans and they all seem to be enjoying it it immensely. There was just a big cheer when George Bush and his wife Laura exited. Europeans are looking for a new mood of consensus, they want action on climate change, they want changes on Guantanamo and the war in Iraq.
Marian Burros in The Caucus:
It was 4 a.m. and bone-chilling cold when the van from Design Cuisine commenced its high-security expedition into the capital from Virginia. Their mission was lunch for 234 guests, including the newly sworn in President Barack Obama and Vice President Joseph R Biden Jr... The menu will continue the Abraham Lincoln thread that has run through Mr Obama's campaign for the presidency, the transition and the Inauguration festivities. It was modeled after a Lincoln menu: Seafood stew en croute. Brace of American birds - duck and pheasants on a bed of vegetables: brussel sprouts, cabbage, carrots and spinach - and a wild cherry chutney. Corn muffins baked in a corn husk. Apple cinnamon sponge cake and sweet cream glace. Read more on The Caucus, NYTimes.com.
1334 In Statuary Hall, the strains of Hail to the Chief are heard again, as President Obama is welcomed with sustained applause.
The White House blog:
Welcome to the new WhiteHouse.gov… A short time ago, Barack Obama was sworn in as the 44th president of the United States and his new administration officially came to life. One of the first changes is the White House's new website, which will serve as a place for the President and his administration to connect with the rest of the nation and the world. Millions of Americans have powered President Obama's journey to the White House, many taking advantage of the internet to play a role in shaping our country's future. WhiteHouse.gov is just the beginning of the new administration's efforts to expand and deepen this online engagement. Read more on The White House blog.
I wish him all the best but have few expectations. He is just a man, a politician no less. His success owes more to his heritage than his experience. More of your comments.
1322 The helicopter carrying former President Bush lands at Andrews Air Force base. Mr Bush shakes hands with military officials as he leaves the aircraft and heads, hands in pockets, across the tarmac to have his picture taken with a group of Air Force personnel.
1320 BBC North America editor Justin Webb:
On the Mall the moment of magic was the moment he (finally) got to the end of the oath. Tears and kisses all around. America has shown the world how it will treat this new force in the land at least in the early days but the world has yet to respond.
1318 The BBC's Steve Schifferes on the Mall: Overheard in the crowd: "It can only go downhill from here."
1317 Our live stream of BBC television coverage is now running again. Refresh your page to pick up the player.
1311 Members of Congress are joining the new president for lunch in the Capitol's Statuary Hall. One of the most-visited rooms of the Capitol, the hall is ringed by statues of prominent Americans. The lawmakers will tuck into a menu inspired by the tastes of President Abraham Lincoln.
Christopher Burdett, Agoura Hills, US:
I am not expecting anything of substance from the new administration and as Obama hasn't made clear what he intends to do, it's hard to tell if he will live up to expectations. More of your comments.
1308 The BBC's Asif Farouk in Islamabad: Even though it was late in Islamabad, people came out of their homes to cafes, to watch the inauguration. In Pakistan people do generally have a feeling of hope, hope for change in America, and they feel that the relationship between Pakistan and America would go through a drastic change. We have had lots of problems recently with the difficulties in the northern part of the country, because of the war on terror… and in Pakistan they hope that this speech by Obama will mean something for change.
1306 The BBC's Karen Allen in Kogelo, Kenya: Barack Obama's ancestral village has been ignited by celebration. Thousands have thronged to join in the festivities and to dance under a massive banner, which simply reads "Congratulations our son our hope." Never has US politics mattered so much to the people of Africa, but this evening the swearing in of the first African-American President has infused hope into the hearts of millions of people across the continent.
Amber, Seattle, US:
The desire to have pride and faith in a governmental leader is a tradition in the US. It is difficult to remember that hero worship is often a mask for incompetency. A "change" will be hard to manage considering the war cabinet remains the same. More of your comments.
1304 President Obama heads back into the Capitol to sign the first official documents of his presidency - the nomination papers for members of his cabinet. "You have a very distinctive signature," Senator Feinstein is heard to say as he puts pen to paper.
1303 The BBC's Kevin Connolly at the Capitol: At moments like this, America reveals a slightly surprising taste for pomp and pageantry, but it's hard to do protocol when the temperature never gets above freezing. America's entire political establishment briefly gathered outdoors to hear Obama's oath but was quick to shuffle back inside the Capitol the second the ceremony was over.
Rozana, Porto Alegre, Brazil:
I hope that God will protect President Barack Obama and give him courage, dignity and an open mind to convince nations that "the time has come" and now we can live together as equals. YES WE CAN! More of your comments.
Well done America - would be happy to see you lead again with Obama in charge. Brown - get some new speech writers! Read AJAG's tweets.
1256 Mr Bush and Mr Obama embrace as the former president and Mrs Bush climb the steps of the waiting helicopter. Mr Bush waves briefly at the top. The Obamas and Bidens stand on the East steps of the Capitol as the helicopter takes off, another symbol of the great change that has come to Washington.
M Kamrul, Nha Trang, Vietnam:
Obama. It is a great challenge to change the world. But we hope you will be the perfect man to take all these challenges. You really are a good star! More of your comments.
1250 The newly inaugurated president escorts his predecessor through the US Capitol building, from West to East. Former President Bush will leave in a helicopter for Andrews Air Force base in Maryland. Former Vice President Cheney will leave by car. Meanwhile, on the Mall, thousands begin to drift away, although more remain.
Never cried so much during the national anthem in my life ... Oh man. I am so proud to be an American. So proud. Read GeekyChic's tweets.
Jibran, Islamabad, Pakistan:
Fingers crossed for the next few years. How much influence can he wield over congress? Can he really change the world? God speed Barack. More of your comments.
1247 The BBC's Clive Myrie says President Obama's speech was very well received on the Mall itself. There were tears on many people's faces, our correspondent says.
Tim Grosvenor, Zurich, Switzerland:
I was so happy to hear his speach. I hope that people listened to the need to keep values of freedom not just power. I am hopeful that he will bring people together. More of your comments.
1245 Our live video streaming is currently down, but we hope to have it back for you shortly.
1240 The BBC's Matt Frei overlooking the Capitol: The US Navy Sea Chanters lead the singing of the US national anthem which brings the ceremony to a close. There can be few occasions when so many have gathered in one place to sing the words.
1239 "Will all those who love justice and mercy say Amen, and Amen and Amen," the Rev Lowery ends. Thousands of voices join in the prayer.
Tony, Yorkshire, UK :
Only words, but magnificent ones. I am certain he will be America's greatest president for generations. More of your comments.
Arjun, Bangalore, India:
The swearing-in ceremony of Barack Obama is the first ceremony to be watched by billions in 2009. I am proud that I am one among them. More of your comments.
1236 Minister and civil rights leader Rev Joseph Lowery gives the benediction. "We pray now, oh Lord, for your blessing upon your servant, Barack Obama, 44th President of these our United States," he says.
1235 BBC Washington correspondent Richard Lister:
It was a sober address, full of rhetorical flourish. This speech is a taste of things to come; tough choices, sacrifice, and hard work, to pull America through its current crises.
1230 The BBC's Matt Frei overlooking the Capitol: He struck a most businesslike tone. This is a man who takes office with an enormous in-tray of problems. What he has told us is that he will take this crisis and turn it into an opportunity.
His voice rising, Mr Obama reaches the climax of his speech: "Let it be said by our children's children that when we were tested we refused to let this journey end, that we did not turn back nor did we falter; and with eyes fixed on the horizon and God's grace upon us, we carried forth that great gift of freedom and delivered it safely to future generations." He asks God to bless America, and once again there is wild applause from the thousands on the Mall.
1227 BBC Washington correspondent Richard Lister:
His speech is almost over by the time he refers to his own race - he has never wanted this to define his presidency.
1226 "With hope and virtue, let us brave once more the icy currents, and endure what storms may come."
1225 "... A man whose father less than 60 years ago might not have been served at a local restaurant can now stand before you to take a most sacred oath."
1225 BBC Washington correspondent Richard Lister:
He signals a very different worldview from that of his predecessor stating that America cannot keep consuming the world's resources "without regard to effect".
1224 "What is required of us now is a new era of responsibility - a recognition, on the part of every American, that we have duties to ourselves, our nation, and the world..."
1223 "Our challenges may be new... But those values upon which our success depends - hard work and honesty, courage and fair play, tolerance and curiosity, loyalty and patriotism - these things are old."
1222 "For as much as government can do and must do, it is ultimately the faith and determination of the American people upon which this nation relies."
1221 BBC Washington correspondent Richard Lister:
His talk of America's military power is a contrast with the Bush years, peppered with words like prudence, humility and restraint. He makes clear that America is not entitled to do as it pleases.
1220 "To the Muslim world, we seek a new way forward, based on mutual interest and mutual respect."
1220 "We are a nation of Christians and Muslims, Jews and Hindus - and non-believers."
1219 "For those who seek to advance their aims by inducing terror and slaughtering innocents, we say to you now that our spirit is stronger and cannot be broken; you cannot outlast us, and we will defeat you."
1219 "Our security emanates from the justness of our cause, the force of our example, the tempering qualities of humility and restraint."
1218 President Obama says: "And so to all other peoples and governments who are watching today, from the grandest capitals to the small village where my father was born: know that America is a friend of each nation and every man, woman, and child who seeks a future of peace and dignity, and that we are ready to lead once more." Again the Mall is a sea of waving flags.
1218 BBC Washington correspondent Richard Lister:
He is setting out his transformative agenda: creating a new energy infrastructure. The image of "harnessing" the soil is a notable one...
1217 "As for our common defence, we reject as false the choice between our safety and our ideals."
1216 "This crisis has reminded us that without a watchful eye, the market can spin out of control - and that a nation cannot prosper long when it favours only the prosperous."
1215 "The question we ask today is not whether our government is too big or too small, but whether it works."
1215 "Everywhere we look, there is work to be done. The state of the economy calls for action, bold and swift, and we will act - not only to create new jobs, but to lay a new foundation for growth."
More applause greets President Obama as he says: "Starting today, we must pick ourselves up, dust ourselves off, and begin again the work of remaking America."
1212 "In reaffirming the greatness of our nation, we understand that greatness is never a given. It must be earned," the president says.
"Today I say to you that the challenges we face are real. They are serious and they are many. They will not be met easily or in a short span of time. But know this, America - they will be met," President Obama says, to huge applause.
1210 There is a reverent silence. Mr Obama begins. "I stand here today humbled by the task before us, grateful for the trust you have bestowed, mindful of the sacrifices borne by our ancestors," he says. "I thank President Bush for his service to our nation".
Guillaume, Princeton, New Jersey, US:
Election day was in the middle of my midterms, and inauguration day is in the middle of my finals. But that won't stop me from watching the great man speak! More of your comments.
As Mr Obama prepares to address the crowd, loud cheers continue. That now familiar refrain of "O-bam-a" goes up again then quiets as the president opens his address.
Kathryn Jean Lopez in The Corner:
Wouldn't it have been something if the majority of the VIPs and those gathered on the Mall had joined Rick Warren in praying "Our Father..."? Among other things, it would have made me more comfortable with the spontaneous "Obama" chants I've been hearing all morning. Read more on The Corner in National Review Online.
1206 Mr Obama, his hand on Abraham Lincoln's Bible, speaks the inaugural oath: "I Barack Hussein Obama do solemnly swear that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect, and defend the Constitution of the United States." He stumbles over his early words, but is congratulated by Chief Justice John Roberts on becoming the new president of the United States.
1204 There is a musical interlude. Cellist Yo-Yo Ma, violinist Itzhak Perlman, pianist Gabriela Montero and Anthony McGill on clarinet play an arrangement by John Williams. Another huge cheer goes up at the piece ends. The inauguration is running several minutes late.
1203 The BBC's Rajesh Mirchandani on Pennsyvania Avenue: No-one on the parade route can see a video screen but thousands are standing still and silent, listening to every word on giant speakers.
Rose, North Carolina, US:
Obama is just a man, he will not be able to fix everything and he will surely make some mistakes. However, he is intelligent, reserved, hopeful, respectful, and has the outstanding ability to connect with people. This is a day to celebrate. More of your comments.
1159 Joseph Biden raises his right hand and takes the vice presidential oath.
1158 Aretha Franklin, "The Queen of Soul", takes to the microphone to sing a soulful version of "My Country 'Tis Of Thee", wearing a dark hat with a huge bow.
1157 BBC Washington correspondent Richard Lister:
Dr Warren talked of God's compassion for everyone - a counterpoint perhaps to the controversy over his objection to gay marriage, which caused liberals to object to his role in this ceremony.
1153 Dr Rick Warren, pastor of the Saddleback Church in California, gives the invocation. He says that "we rejoice not only in America's peaceful transfer of power", but celebrate "a hingepoint of history, the inauguration of the first African American" as president of the United States.
1152 BBC Washington correspondent Richard Lister:
The first person the president-elect embraced as he stepped into the bright sunshine of the Capitol steps was Congressman John Lewis, one of the most important figures of the Civil Rights era.
Lucas Skræddergaard, Holstebro, Denmark:
I want to watch history be made. America gets a new president, a new beginning. Obama is the president of my generation. A man who embodies hope for a world gone astray. More of your comments.
Michael Grunwald in Time:
We're letting my 10-month-old son watch tv for the first time, starting now. Max, it's not always this interesting. Read more Michael Grunwald.
1146 Senator Dianne Feinstein, one of the most powerful women in the Senate, opens the ceremony, saying: "We gather to etch another line in the solid stone of history."
1145 Chants of "O-bam-a" echo across the Mall as Mr Obama takes his seat.
Horns are played to mark the formal start of the ceremony. The crowds get their first glimpse of the man who will be the next president of the United States, introduced as "Barack H Obama". The Mall is a sea of waving American flags and a huge roar goes up.
1139 President George W Bush is announced as president for the final time, walking out as Hail to the Chief is played by the US Marine Band. There are muted boos in the crowds on the Mall, but the BBC's Clive Myrie says there is still much respect for the US commander in chief.
1137 Cheers erupt from the thronging crowds as Michelle Obama appears on the inaugural platform.
SF, Cluj-Napoca, Romania:
Obama might be a man with good intentions, but he's not the Messiah. He is a politician, though. And every time people take politicians for rock stars, I'm a bit worried. I don't think this honeymoon will last more than six months. More of your comments.
1132 The BBC's Adam Brookes at the Capitol: Things are running a bit behind time - but there really is an electric atmosphere here.
1131 The BBC's Lucy Williamson in Indonesia: Up on the stage at the inauguration party here in Jakarta, some of the current pupils of Barack Obama's old school are performing a traditional Indonesian dance. You've got to wonder if he still remembers the moves.
1126 The BBC's Jon Sopel says there is a party atmosphere on the Mall. People are cheering when they see someone they like appearing on the inaugural platform. Some security entrances to the Mall have been closed because many thousands of people are still trying to get there to see the ceremony, in just over 30 minutes' time.
1124 France's Foreign Minister Bernard Kouchner warns that Mr Obama will have a great deal of problems to deal with when he takes over the reins of power: "He faces a massive task, even with his great qualities, and I don't think we should expect him to resolve all the problems straight away."
1122 The BBC's Kevin Connolly at the Capitol: For Barack Obama's security people, today is a nightmare. The worst aspect of it is right now - when the incoming and outgoing administrations are gathered together on the Capitol steps. In order to be prepared for a national catastrophe, a single cabinet member stays away from the proceedings to guarantee continuity come what may. This year, Defence Secretary Robert Gates is watching it all on TV at a military installation "somewhere in the United States".
1118 The former presidents arrive for the inaugural ceremony; George HW Bush, with former First Lady Barbara Bush, Jimmy Carter and wife Rosalynn, Bill and Hillary Clinton, for whom this day may be a bittersweet moment.
Clark Judge in Podium Pundits:
In one profound respect, Barack Obama's inauguration is similar to those of Andrew Jackson and John F Kennedy, not so much as a matter of American politics, but of American culture. A group that felt excluded to one degree or another from the American system — Westerners in Jackson's case; Catholics in Kennedy's — saw one of their own rise to the highest rank of American government. And as with today, Jackson's inaugural drew unprecedented crowds. Read more Clark Judge.
AZ, Arizona, US:
I'm keeping an open mind about Obama's presidency. A new face is usually for the best, especially after eight years of a previous president. I do think many people will be disappointed four years from now though. They have such high expectations, but a president can't do it all alone. More of your comments.
1110 President of the European Commission Jose Manuel Barroso issues a statement saying: "I personally believe that the election of President Obama was a defining, turning point for America. It may now also be an important turning point for the rest of the world."
Shelia, Charlotte, US:
This is a happy day. I am thrilled to be able to watch the 44th president of the United States take the oath of office. It is a day of hope and joy. Americans are privileged to observe the ease as the transition of power takes place. Never take this for granted. This is a time to celebrate and tomorrow we will get to work! More of your comments.
1104 Refresh your browser now to pick up the player for our live video coverage of the inauguration of the 44th President of the United States.
1103 The BBC's Kevin Connolly: The VIP enclosure around the podium where Barack Obama will be sworn in is slowly filling with dignitaries. So extraordinary is the sight of the huge sea of people stretching down the National Mall that one or two senators have been taking souvenir photos for themselves. Most notable among the group of senators is John McCain of Arizona, looking perhaps a little wistful. After all, if the election had gone the other way, he would be minutes away from the presidency now.
1100 George W Bush has just one hour left as president of the United States. We are 60 minutes away from the one of the most keenly-awaited inauguration speeches in history. What Barack Obama says here will reverberate throughout America and across the world.
The motorcade passes slowly by the reviewing platform from where, screened by bullet-proof glass, Mr Obama will later watch the inaugural parade. Crowds along the route to the Capitol cheer loudly, their anticipation building palpably ahead of the inaugural ceremony in just over an hour's time.
Tacamo, Paris, France:
I hope the Americans have clearly understood that Mr Obama has no magic wand and "Abacadabra" will not make the world a better place to live in. More of your comments.
1049 The end of an era is nigh, as George W Bush leaves the White House for the last time as president. His face betrays little emotion as, accompanied by Mr Obama, he swiftly steps into a limousine.
1048 Dick Cheney, in a wheelchair, exits the White House for the final time as vice president.
1046 Michelle Obama and Laura Bush emerge from the White House, following their symbolic meeting over coffee, and enter a waiting car.
twitter already starting to fail under the load....I'm not even getting the whale when it does Read PaulLeBlanc's tweets.
1045 The BBC's Kevin Connolly: With less than an hour and a half to go before Mr Obama is sworn in, the dignitaries who will witness this extraordinary moment of transition are being announced and led to their seats, beginning with governors and members of congress, and working all the way up to the man who is now in the last 90 minutes of his presidency: George W Bush. It is bitterly cold but such are the demands of modern security that the eminent people have to sit out in it for some time for the privilege of witnessing history.
1043 The US Homeland Security Department says it is investigating a potential threat to the inauguration, but describes it as "of limited specificity and uncertain credibility".
Carol Platt Liebau in Townhall:
There will be plenty of occasions when I will disagree with President Obama, but like all patriotic Americans, I wish him and his family well. As for President Bush, in my judgment, most of his decisions - and especially the big ones - will be vindicated by history. He did what he thought best for the country, and he kept us safe. Read more on Townhall.
1036 Reports say that the outgoing Vice President Dick Cheney is expected to attend the inauguration ceremony in a wheelchair, after pulling a muscle in his back.
John, Leuven, Belgium:
A fabulous day in history is upon us, as the most powerful nation on Earth celebrates another peaceful transition of power. Wishing Obama, Biden and their whole team the very best, for the sake of the whole world.
More of your comments.
1033 The BBC's Steve Schifferes: The crowd on the Mall is very good-natured. Lots of children, photographs being taken, and shouting for lost friends.
1031 The best seats by the inaugural platform are beginning to fill up. The former presidents - George HW Bush, Jimmy Carter and Bill Clinton - are expected to arrive shortly. The latest pictures have shown the actor Dustin Hoffman taking his place.
James Poniewozik in Time:
How do you know when a politician is having a broad effect on American culture? When he becomes a soft drink. On the TV coverage this morning, I've been seeing Pepsi's newly unveiled ad campaign, which shamelessly borrows the language and graphics of Obama's campaign. "Yes, You Can." Get it? Pepsi. Can... We've had presidents as celebrities before, but I think this is our first president-as-brand. Read more James Poniewozik.
1025 Just a reminder that from 1100 we will be live streaming TV coverage from Washington at the top of this page. You will need to refresh your browser after that time to pick up the video player.
Richard, Kelowna, Canada:
I really hope that Obama speaks about the current climate and the changes that he will put into motion in order to save our planet as we know it. More of your comments.
1021 The BBC's Adam Brookes: The marine band is striking up and the chairs on the inauguration platform are beginning to fill up. Everybody is transfixed at the sight of the mall, packed with what seems to be hundreds of thousands of people.
1018 People on the Mall are telling of stringent security checks. Bags have been checked, coats opened up, people patted down. Guards with cameras have been taking pictures of people's faces as they pass through tents leading to the heart of the celebration. Some 45,000 soldiers, police and security guards are on duty.
About to try out one of the famous portopottys on the mall. I will never forget this moment. Read dnkb's tweets.
SB, Pennsylvania, US:
We need more than fancy speeches to get through this economic crisis. The media has set very high expectations on Obama. If he doesn't deliver on his promises, he'll be just another Bush in office.
More of your comments.
Some ppl think we're making too much of a big deal about this. hate to say it but each one has been white. hmm. just saying. Read douglaspaul's tweets.
Dar, Milan, Italy:
I may be one of the few with low expectations. The speeches are hollow and full of idealism, in certain ways they could even be considered ultranationalist, which is scary in a globalised and civilised world. I also don't like the Hollywood-style PR machine. More of your comments.
1003 On the steps of the Capitol, the San Francisco Girls Chorus choir strikes up, the singers wearing distinctive red hats and scarves, signalling the start of formal inaugural festivities.
0956 The vice president-elect's vehicle is first to draw up to the door of the White House. Two Marine guards standing either side of a bright red carpet salute Mr Biden and his wife as they disappear into the building. There is a small pause, and then Mr and Mrs Obama emerge from a second vehicle to be greeted by George and Laura Bush. Michelle Obama hands over a gift-wrapped box and the quartet pose for photographs.
0954 The many vehicles in the Obama motorcade make their way slowly towards the White House where the president-elect will join President Bush and the First Lady for coffee.
0953 BBC Washington correspondent Kevin Connolly: There is a heavy turn out of African-American celebrities. In the media trailer park Denzel Washington brushes past us. And on the steps of the Capitol a few feet from the podium, the ebullient boxing promoter Don King holds court. He tells me they'd be speaking German in France these days if it wasn't for American GIs in World War II and he calls Obama "a beacon of light".
0950 The Obamas leave St John's church, waving to onlookers. Mr Obama escorts Michelle to their limousine and then walks around to enter the other side of the vehicle.
Nikon in The Huffington Post:
Hello to all from warm & sunny Kingston, Jamaica. We are all excited that a new day is about to dawn in US politics. We hope things will get better for all. Read more on The Huffington Post.
0947 In Barack Obama's ancestral village in Kenya, the time is around 1745. The latest pictures show people in great spirits, dancing into the evening in traditional dress and in everyday clothes. Mr Obama's Kenyan grandmother is not there. She and many of his relatives have made the journey to Washington.
0945 The BBC's Steve Schifferes: Spontaneous cheers of O-O-Obama as I walk by the Washington Monument.
Regina-Gabrielle Berry, Toronto, Canada:
I have absolutely no expectations for the Obama presidency. The American people are desperately seeking someone to follow, someone to tell them what to do. Obama has got to do more than call on all Americans to adopt "a new era of responsibility". He has got to introduce "a new era of responsibility". He has got to be a role model and a leader. More of your comments.
British Foreign Secretary David Milliband tells the BBC that the inauguration of Barack Obama "reflects a yearning for a new start" in America. He also recalls attending school in 1970s Boston, and says he would have been "incredibly surprised" to hear then that there would eventually be a black president of the United States.
Hopefully we the people can come together (once again) to form a more perfect union. Read mzfeefee tweets.
BBC North America editor Justin Webb:
A woman on the Washington Metro taps me on the shoulder. I thought I might be treading on her foot. But no: "I am so sorry I am pressing against you!" These out of town folks are unused to public transport. Most Americans are, but the Washington Metro is coping pretty well so far - aided by the sheer joy of the travellers. Perhaps all rush-hours for the next 8 years will be celebrations.
0932 Hundreds of seats in front of the US Capitol building, at the head of the main crowd, currently stand empty, reserved for dignitaries and invited guests who will get a close-up view of Mr Obama as he takes to the inaugural platform.
Million Birru, Addis Ababa, Ethiopia:
Barack is a hope for everyone. He is a winning spirit for every person, white or black. If you think that you are not doing well, you can think of him. So I wish him good luck and let God be with him. More of your comments.
0925 The National Mall, from the Lincoln Memorial almost to the Capitol itself, is currently a sea of people, many dressed for the cold in Stars and Stripes woolly hats, and many waving miniature American flags. Police estimate the size of the inaugural crowd is between one and two million.
0920 BBC Washington correspondent Kevin Connolly:
From our vantage point in the makeshift amphitheatre of seating erected on the steps of the Capitol building, we have exactly the same view of Washington DC that Barack Obama will enjoy if he lifts his eyes from Lincoln's bible as he is sworn in a few hours from now. Already it is a breathtaking site. Every inch of space between the American capital's famous landmark is slowly filling with a multicoloured sea of people who have surged into the city centre.
Wangxiaoyuan, Jilin, China :
It is as clear as crystal that the new president will bring some luck to the US. I hope President Obama can fufill his promises to give people all over the world a peaceful situation. However, things don't always go according to one's wish, so President Obama should build a team which has the same dream. More of your comments.
W. James Antle, III in The American Spectator blog:
The legacy of Bush is making the election of Barack Obama - a freshman Illinois senator who was in the state senate when the planes crashed into the Twin Towers and Pentagon - possible. Whatever the failings of the incoming president, he would not be in the White House were it not for the failures of the outgoing president. Best wishes to both of them.
Read more W. James Antle, III.
0915 In less than three hours' time, Mr Obama will become the US's first African-American president, taking the oath of office with the same Bible used in 1861 by Abraham Lincoln, whose presidency brought about the end of slavery in America. The BBC's Clive Myrie, on the Washington Mall, says there appears to be a far greater number of African Americans in the crowd than for the last presidential inauguration.
Megan, Cheshire, UK:
Good luck Obama, let's see if good speechmaking translates into good leadership. More of your comments.
0912 Whatever he achieves in the long term, Barack Obama's inauguration may not be the best thing for US productivity on Tuesday: The latest polls suggest three out of four Americans plan to watch the ceremony. But millions are also tuning in around the world. In the Kenyan capital, Nairobi, celebrations have already been taking place for the nation's favourite son.
Hekmatt, Al Khobar, Saudi Arabia:
I pray President Obama measures up to the expectations of humanity. A major challenge awaits President Obama. Restoring the values of credibility, integrity and decency, once the pillars of America. More of your comments.
K Tyson, US:
I would never have voted for Obama due to his economic stance. However, I will be watching. This is history. One generation is handing over to another. More of your comments.
0903 As many thousands of people gather for the historic ceremony, braving sub-zero temperatures on Washington's National Mall, President-elect Obama, Vice President-elect Biden and their families are attending a service at St John's Church, opposite the White House. They arrived in a convoy of black limousines, a smiling Mr Obama wearing a dark suit, and his wife Michelle in a yellow frock coat.
Jason G, Washington, US:
Obama has the charisma and intelligence to be a great "uniting" entity. For now, we have something we haven't had in quite a while, hope and optimism. More of your comments.
Robert G, Virginia, US:
Although I didn't vote for him, Obama has my full support as our elected president. More of your comments.
0900 Welcome to our live coverage of the inauguration of Barack Obama as the 44th President of the United States. We will be constantly updating this page throughout the day, bringing you insights from the BBC's Richard Lister in Washington and other BBC correspondents, some of your emails and Twitter, and the best of the blogs. From 1100 we will be streaming live BBC television coverage from Washington DC.