WASHINGTON - A world weary of wars and ravaged by a global economic meltdown turns its eyes to Barack Obama on Tuesday as he becomes the first black president in America's 233-year history.

Americans sobered by enduring conflicts in Iraq and Afghanistan will not be alone in counting on the new U.S. president to deliver on the renewed era of hope he's promised since his momentous electoral victory in November.

With his hand on Abraham Lincoln's Bible, his wife and children by his side, Obama will take the oath of office - reportedly reciting his full name, Barack Hussein Obama - to become the 44th president of the United States before making his way to the ornate presidential residence constructed by slaves more than 200 years ago.

A veritable sea of humanity will be cheering him on every step of the way. As many as four million people, some of them from countries all over the globe, are expected to be on hand.

They will gather between the city's iconic Capitol building where Obama will deliver his highly anticipated inaugural address, spill down the grassy stretch of land known as the National Mall to the Lincoln Memorial, all of them eager to take part in a profound chapter of American history.

The celebrations were already in full force in D.C. on Monday, as thousands wandered the city's streets snapping pictures, buying Obama merchandise and lining up for two hours for a chili dog at Ben's Chili Bowl, the popular D.C. landmark made even more famous by the president-elect's impromptu visit there 10 days ago.

His historic inauguration comes after eight years of divisive and unpopular Republican rule under George W. Bush that saw the United States become embroiled in two protracted and unpopular wars and left it teetering on the precipice of another Great Depression.

There were almost as many in the throngs of people in D.C. on Monday celebrating the end of the Bush era as there were those high-fiving one another at the notion of at least four years of an Obama presidency.

Some carried signs or wore T-shirts emblazoned with "Arrest Bush."

At midday, when emergency vehicles raced past in the direction of the White House, a rumour passed quickly through the chattering crowd that someone had thrown a shoe over the wrought-iron gates surrounding the presidential residence.

Shoe-throwing has become a fad since an Iraqi journalist caught worldwide attention by tossing his shoes at Bush during a news conference in Baghdad last month. Earlier Monday, an anti-Bush organization erected a 10-metre-high balloon of the outgoing president and urged passersby to hurl shoes at it.

Despite the euphoria, however, Obama has been careful to remind Americans - in almost all his public remarks since winning the election - of the mammoth challenges confronting him and the country in the face of an ongoing economic meltdown.

Canadians, it seems, are among those who believe he's got the right stuff to lead the U.S. out of the darkness of the past eight years.

Fifty-seven per cent of Canadians believe Obama will do even better than expected, according to a recent The Canadian Press-Decima Research poll. Sixty-eight per cent of them also forecast a second term for Obama.

In an interview with the Washington Post published on Monday, Obama said he hoped to use his presidency as an example of how people can bridge differences, racial and otherwise.

"What I hope to model is a way of interacting with people who aren't like you and don't agree with you that changes the temper of our politics," Obama said.

"And then part of that changes how we think about moving forward on race relations. Race relations becomes a subset of a larger problem in our society, which is we have a diverse, complicated society where people have a lot of different viewpoints."

His promised approach is something of a foreign concept in Washington, and partly explains the euphoria that has been evident in the celebrations leading up to Tuesday's swearing-in ceremony.

"It feels like we're coming out of the Dark Ages into a whole Renaissance period," Sam Farr, a Democratic congressman from California, said recently.

"The fear is that the expectations are that one person can be magical, but these are still human beings running this country and subject to all of the frailties of mankind. But there's a spirit of hope here, a spirit of excitement among us all."

Even Republicans say Obama is making all the right moves.

Vermont Gov. James Douglas, who met Obama recently at a gathering of the National Governors Association, says he's been impressed with Obama's efforts to work across party lines.

"He said to us that there's a time for politics and a time to govern," Douglas said. "He reached out, particularly to the Republican governors, assuring us that he wants to hear our views. He said: 'I'll listen even more intently when we disagree."'