President-elect Barack Obama has started forming his White House administration by appointing Rahm Emanuel, a former adviser to President Bill Clinton, to be his chief of staff.
Mr Emanuel, an Illinois congressman and tough Washington insider, will be responsible for much of the internal management of the new administration.
He is known for his tough and aggressive style in the political arena, and has been dubbed "Rahmbo" by some US media.
Regarded as a centrist Democrat, Mr Emanuel, 48, was an important player in the $US700 billion financial bailout plan, where he helped mobilise Democratic votes to pass the measure.
He has had a rapid rise up the party hierarchy since his election in 2002 as Congressman for Illinois' Fifth District in Chicago.
However, critics say his appointment could accentuate party divides, rather than heal them, as Mr Obama has pledged.
In a profile of Mr Emanuel in Rolling Stone in 2005, former Bill Clinton staffer Paul Begala said: "He's got this big old pair of brass balls, and you can just hear 'em clanking when he walks down the halls of Congress."
Timothy Geithner, president of the Federal Reserve Bank of New York, former Treasury Secretary Lawrence Summers and former Federal Reserve Chairman Paul Volcker are among those being considered for the key Treasury post.
Mr Obama was elected the first black American president on Tuesday, with a resounding win over his Republican rival John McCain.
In a late result, Mr Obama is projected to take North Carolina.
The win would give him 15 extra electoral college votes, increasing his total to 364. Mr McCain has 152 so far. Missouri is now the only state that remains too close to call.
With most precincts tallied, Mr Obama's share of the popular vote stands at 52.3% compared with Mr McCain's 46.4%.
Turn-out was reported to be extremely high - in some places "unprecedented" in what many Americans said they felt was an historic election. It was predicted that 130 million Americans had voted - the highest turn-out since 1960.
The entire US House of Representatives and a third of US Senate seats were also contested in the elections.
The Democrats increased their Senate majority by five seats, but fell short of the 60 needed to stop blocking tactics by Republicans.
They also increased their majority in the House of Representatives, gaining 20 seats to give a total 252, leaving the Republicans with 173.
Iran's olive branch
Iran's hardline President Mahmoud Ahmadinejad congratulated Mr Obama and called for "fundamental and fair" changes to US policies in the region.
The message of congratulation is rare, possibly unprecedented, the BBC reports, as Iran and the US are more used to trading insults.
President George W Bush labelled Iran part of the "axis of evil" and Iran has long called America "the great satan".
The two countries have since been at odds over various issues, including Iran's nuclear programme, which Washington and its European allies say is a cover to build nuclear bombs.
Iranian officials have said Mr Obama's election victory showed the American people's desire for fundamental change in domestic and foreign policy from the policies of Mr Bush.
"The great Iranian nation welcomes real, fundamental and fair changes in America's behaviour and policies, particularly in the Middle East region," Mr Ahmadinejad said.
He called on the US to change its policies, stop warmongering and to take steps to reclaim a sense of honour and hope.
It is widely thought that Mr Ahmadinejad wants to open a dialogue with the US.
Mr Obama has said he would toughen sanctions on Iran but has also held out the possibility of direct talks to resolve rows, including Tehran's nuclear dispute with the West.