A massive concert's been held in Washington to welcome Barack Obama before he officially becomes America's 44th president on Tuesday.
Hundreds of thousands of supporters turned out to see their new president and watch performances from big name stars like Beyonce, Shakira and Usher.
Obama told everyone watching that "anything is possible in America".
But he also warned that the country was facing its toughest challenges in years and solving them would take time.
Beyonce was on the star-studded list of performers at the concert
The We Are One concert is one of a series of special events that's being held in the run-up to the main ceremony - called the Inauguration - on Tuesday, when he officially takes over as president.
About 240,000 tickets have been issued for Tuesday's celebrations, but people are so excited about Obama's presidency that officials are expecting up to two million people to turn up.
To cope with all the people, a road which stretches nearly two miles from the Capitol to the Lincoln Memorial will be opened to the public for the first time.
And thousands of police officers are believed to be involved in one of the biggest security operations Washington has ever seen.