Barack Obama has been re-elected president of the United States, convincingly defeating his Republican challenger Mitt Romney.
Addressing his supporters at a rally in Chicago in the early hours of Wednesday morning, Obama said Americans had "voted for action, not politics as usual".
Walking on stage with his wife Michelle and his daughters Malia and Sasha, Obama insisted: "The best is yet to come, but we have more work to do."
"Tonight, more than 200 years after a former colony won the right to determine its own destiny, the task of perfecting our union moves forward.
"Whether I earned your vote or not, I have listened to you. I have learned from you. You have made me a better president and with your stories and your struggles I return to the White House more determined and more inspired than ever.
"I believe we can seize this future together, because we are not as divided as our politics suggest," he said to cheers from the crowd. "We are an American family and we rise or fall as one nation or one people."
Returning to the theme that launched him onto the national stage in 2004, he concluded: "We remain greater than a collection of red states and blue states, we remain the United States of America."
Obama secured at least 303 out of the 270 electoral college votes needed for victory by snatching wins in the crucial swing states including Ohio, Colorado, Virginia, New Hampshire and Wisconsin.
By contrast Romney only won two states more than John McCain did when he lost to Obama in 2008 - Indiana and North Carolina,
Immediately after the major TV networks declared him the winner just after 11pm EST, President Obama tweeted his thanks to voters, including the message "four more years" and a picture of him hugging his Michelle.
In an email to his supporters accompanying the Tweets Obama said: "Today is the clearest proof yet that, against the odds, ordinary Americans can overcome powerful interests. There's a lot more work to do."
He added: "You organized yourselves block by block. You took ownership of this campaign five and ten dollars at a time. And when it wasn't easy, you pressed forward.
"I will spend the rest of my presidency honoring your support, and doing what I can to finish what we started."
However while Obama secured a healthy win in the electoral college, the popular vote nationwide was far closer. At the time of writing Obama had won 49,477,410 votes while Romney was only slightly behind on 49,463,852.
In an embarrassment for the Republican ticket both Romney and his vice presidential running mate Paul Ryan lost their home states of Massachusetts and Wisconsin.
In his concession speech in Boston, Romney told supporters: "I have just called Obama to congratulate him on his victory.
“This is a time of great challenges for America and I pray the president will be successful in guiding our nation."
"I so wish that I had been able to fulfill our hopes to lead the country in a different direction but the nation chose another leader."
Voter turnout was reported to be high, with long queues at some polling stations following the most expensive presidential battle in US history at a cost of £1.3 billion.
Aside from the presidential contest the picture painted by other election results was of a increasingly liberal America. Voters elected their first ever openly gay senator in Tammy Baldwin as other states voted to legalise gay marriage.
And in Colorado and Washington voters decided to legalise recreational marijuana, while medical marijuana was also legalized in Massachusetts.
The Democrats also managed to retain control of the Senate. The consolation prize for the Republican Party was the House of Representatives, where it remains in the majority.
In the Missouri Senate race Todd Akin lost to Democrat incumbent Claire McCaskill. The contest shot to international attention after Akin said abortion should be illegal, even in cases of rape.
Akin was leading McCaskill in the polls until he said in August that victims of "legitimate rape" rarely get pregnant, because the female body "has ways to try to shut that whole thing down."
McCaskill’s victory victory helped the Democrats defend their majority in the Senate. The party also won back a seat in Massachusetts and captured a Massachusetts seat with Elizabeth Warren declared the winner over GOP incumbent Scott Brown.
In Indiana, which should have been an easy win for the Republicans, Democrat Joe Donnelly beat Richard Mourdock. Donnelly’s win has been attributed to his rival’s claim that pregnancies from rape were something "God intended to happen."