The Republicans - they're a bit like the Conservatives in the UK
Married to Cindy, with seven children
Dancing Queen by Abba
He first tried to be the Republican candidate back in 2000, but his party chose George Bush instead.
Before getting into politics, he was a pilot in the American Navy.
In the 1960s, his plane was shot down during America's war in Vietnam and he was captured and held prisoner for five-and-a-half years.
When he was released he was given medals for bravery and made an American war hero.
He says climate change is real and devastating and was willing to spend more money on trying to sort it out.
He also thinks America should consider joining with every other nation in the world to reduce greenhouse gas emissions, if China and India join in.
War in Iraq
McCain was in favour of the war in Iraq and, if he'd won, would have kept American troops over there for as long as they're needed.
If he had won, he would have been the oldest new President America's ever had.
He said his age meant he's got lots of experience and reckoned that right now that's what America needs most.