President Barack Obama has been re-elected to a second term, defeating Republican challenger Mitt Romney.
America's first black president secured more than the 270 votes in the electoral college needed to win.
In his victory speech
before supporters in Chicago, Mr Obama said he would talk to Mr Romney
about "where we can work together to move this country forward".
Mr Obama prevailed despite lingering dissatisfaction with the economy and a hard-fought challenge by Mr Romney.
His Democrats also retained their majority in the Senate, which they have held since 2007.
The Republicans kept control of the House of
Representatives, which analysts say will likely result in more of the
gridlock that characterised Mr Obama's first term, with the House and
the president at loggerheads on most legislation.
In his address, the president challenged his opponents, asking them to work with him.
With only Florida's 29 electoral votes still undecided, Mr Obama won 303 electoral votes to Mr Romney's 206.
The popular vote, which is symbolically and politically important but not decisive in the race, remains very close.
'One nation' speech
Mr Obama congratulated Mr Romney and Republican vice-presidential candidate Paul Ryan on their hard-fought campaign.
"We have picked ourselves up, we have fought our way back and
we know in our hearts that for the United States of America the best is
yet to come," he said.
Mr Obama said he was returning to the White House "more
determined, and more inspired than ever about the work there is to do,
and the future that lies ahead".
He pledged to work with Republican leaders in Congress to
reduce the government's budget deficit, fix the tax code and reform the
immigration system.
Referring to the struggling economy, Mr Romney
said now was not the time for "partisan bickering and political
posturing", and that Republicans and Democrats must "put people before politics".
"I so wish that I had been able to fulfil your hopes to lead
the country in a different direction but the nation chose another leader
and so I join with you to earnestly pray for [Mr Obama] and for this
great nation," he said.
Under the US constitution, each state is given a number of
electoral votes in rough proportion to its population. The candidate who
wins 270 electoral votes - by prevailing in the mostly winner-takes-all
state contests - becomes president.
On Tuesday, the president held the White House by assembling
solid Democratic states and a number of important swing states such as
Colorado, Iowa, Pennsylvania, Michigan, Minnesota, Virginia and
Wisconsin. His narrow victory in Ohio, a critical Mid-Western swing
state, sealed the victory.