Obama to strive for unity in inaugural address

US President Barack Obama, who was yesterday sworn in for four more years in a private ceremony at the Whitehouse, will repeat the oath of office before a crowd of thousands wrapped up against the chill at the white-domed Capitol building, which is draped in huge US flags.

After Obama spent an exhausting first term battling the worst economic storm in decades and waging partisan warfare with Republicans, his second inauguration lacks the historic and hopeful promise of the first in 2009.

Yet Obama, 51, has a legacy to defend, including a historic health care law and a retrenchment from draining wars abroad, and he is vowing to make good on the promise of a fairer economy, which anchored his re-election win.

He signaled at a reception for supporters, that he would dwell on the "common good" and the "goodness, the resilience, neighbourliness, the patriotism," of Americans when he gives his address for history later today.

"What we are celebrating is not the election or the swearing in of the president, what we are doing is celebrating each other and celebrating this incredible nation that we call home," Obama said.

"And after we celebrate, let's make sure to work as hard as we can to pass on an America that is worthy not only of our past, but also of our future. "

Obama's senior advisor David Plouffe said Sunday that the president will ask Americans in his inaugural address to remember what unites them, rather than political divisions which have split the country down the middle.

Obama took the oath of office yesterday to comply with the US Constitution, which dictates his first term ends at noon on January 20.

Tradition states that when that date falls on a Sunday, a private swearing-in is followed the next day by public festivities, including the second oath taking, the address, parade and glittering inaugural balls.

After a tumultuous first term, Obama's status as the first African American president in a nation born on a racial fault line almost seems like an afterthought now -- perhaps a sign of progress.

But poignantly, Obama will takes his second, second term oath of office on Martin Luther King day, the federal holiday marking the civil rights pioneer's birthday.

He will rest his left hand on a Bible once owned by King, and another which once belonged to his hero Abraham Lincoln, the president who ended slavery.

And in another historic echo, Obama will become the second president to be sworn in four times -- thanks to the Roberts stumble in 2009 and his double oath duty this year, joining Democratic icon Franklin Roosevelt.