Barack Obama first commented on his victory via Twitter. His picture of himself and wife Michelle, with the tag line "Four more years," quickly became the most retweeted message ever.
- [GABRIEL BOUYS/AFP/Getty Images]

Barack Obama held his victory rally at McCormick Place in Chicago, Illinois, the state where he began his political career.
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Barack Obama gave his second victory address in front of hundreds of Democrat supporters.
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President Barack Obama told Americans: "Tonight, despite all the hardship we've been through, despite all the frustrations of Washington, I've never been more hopeful about our future. I have never been more hopeful about America."
- [Win McNamee/Getty Images]

Joe Biden celebrated winning another four years as Obama's vice president.
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First Lady Michelle and their daughters, Malia and Sasha, joined President Obama on stage.
- [Spencer Platt/Getty Images]

Republican candidate Mitt Romney, meanwhile, conceded defeat at the Boston Convention & Exhibition Center in Massachusetts, the state he once governed. Last night the state voted for Obama.
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Mitt Romney on stage with his wife Ann, running mate Paul Ryan and Ryan's wife Janna.
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A disappointed Romney supporter in Boston.
- [Emmanuel Dunand/AFP/Getty Images]

The mood couldn't have been more different in Times Square, New York, where Obama supporters cheered as his win was announced.
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People also celebrated Obama's victory all over the world. Here, Indian artist Suduran Pattnaik finished a sand sculpture of the president in Puri, India.
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In Ivory Coast, this Abidjan butcher has named his store "The White House" - the sign with a picture of Barack Obama is good for another four years.
- [Sia Kambou/AFP/Getty Images]

In Indonesia, people pose with a cardboard cutout of President Obama at the US Embassy in Jakarta.
- [Romeo Gacad/AFP/Getty Images]

In Kenya, the home of Obama's father, the president's step-grandmother Sarah celebrates his victory with other relatives in the village of Kogelo.
- [Tony Karumba/AFP/Getty Images]