Tracing the arc of history to a day many thought would never come, Barack Obama is to be sworn in as America's 44th and first black president at 1am tomorrow - and wade into a sea of troubles.

Climaxing the unlikeliest of journeys, Obama, the son of a black Kenyan and white mother from Kansas is at noon (1am Malaysian time) to take the oath of office on the steps of a Congress building founded on slave labour.

barack obama presidential inauguration day 200109 05 Guarded by an unprecedented security operation, millions are expected to pack the National Mall stretching from Capitol Hill to the Lincoln Memorial - where Martin Luther King, in 1963, spoke of a dream of racial unity.

To his successor, President George W Bush bequeaths an economy in crisis, war on two fronts and a patchwork of frayed alliances. For Obama, drawing inspiration both from Abraham Lincoln and Franklin D. Roosevelt, the perils of the age call for a spirit of national sacrifice unseen since World War II.

"Tomorrow, we will come together as one people on the same mall where Dr King's dream echoes still," Obama said on Monday, paying tribute to the slain civil rights hero on the national holiday commemorating King's birth.

"As we do, we recognise that here in America, our destinies are inextricably linked.

"We resolve that as we walk, we must walk together. And as we go forward in the work of renewing the promise of this nation, let's remember King's lesson - that our separate dreams are really one."

First handover since Sept 11 attacks

On Tuesday morning, in the first presidential handover since the Sept 11 attacks of 2001, Obama and his wife Michelle are to meet the departing president and First Lady Laura Bush at their new home in the White House.

Then after swearing to "preserve, protect and defend" the US constitution, Obama is to deliver his most important speech yet in a career littered with memorable oratory since his explosion onto the national stage in 2004.

barack obama presidential inauguration day 200109 03 Braving the cold, a vast crowd is expected to line the Mall, watching the inauguration either near the West Front of the US Capitol for the lucky few, or in front of giant TV screens for the rest.

Renita King, 46, said she had flown from Houston, Texas with her six-year-old son Arthur to mark the years of racial prejudice endured by her 73-year-old mother.

"I am here for her, and every time that she was called a nigger - that is how I see this, as an American," she said.

barack obama presidential fever 200109 02 Aides said Obama's call for all Americans to embrace public service would dominate his inaugural address, as he gets to grips with the nation's longest recession since World War II and his plans to pull US troops out of Iraq.

Bush's White House said Defence Secretary Robert Gates would sit out the inauguration at an undisclosed location as the "designated successor" in the event of a catastrophe.

Both the vice-president and the House speaker - the No 2 and 3 designated succesors - will be at the inauguration.

Gates was a fitting choice: Bush chose him to be his defence secretary in November 2006, and Obama has decided to keep him on at the Pentagon to tackle the withdrawal from Iraq and launch a new offensive in Afghanistan.

Obama's groaning in-tray of challenges

The "war on terror" is just one part of Obama's groaning in-tray of challenges. From Gaza to Guantanamo, he confronts a world in tumult, a point underscored by the latest bellicose noises from nuclear-armed North Korea.

barack obama presidential fever 200109 04 Following the inauguration of Obama and vice president-elect Joseph Biden, the new US leaders are to lunch with members of Congress, Supreme Court justices and Obama's cabinet, including secretary of state Hillary Clinton.

Marching bands, military veterans, union workers and schoolchildren are to then join a parade down Pennsylvania Avenue to the White House for Obama to take up the reins of power in the Oval Office and his place in history.

barack obama presidential fever 200109 05 The whirlwind day will climax in 10 official inaugural balls before the Obamas can retire with their daughters Malia and Sasha, becoming the youngest First Family since John F Kennedy occupied the White House in the early 1960s.

The celebrations have an acute piquancy for many in the United States, and the world, given Obama's mould-shattering bi-racial heritage.

But the new administration has no time to rest on its laurels. Obama aides have spelt out an action-packed first week, topped by action in Congress to pass a US$825 billion economic stimulus plan. - AFP