Obama sworn in as 44th US President

Barack Obama strode to the pinnacle of American power on Tuesday, taking the oath as the 44th US president and shattering racialu00a0barriers as the first black leader of the country.

He took over a nation longing for change after President George W Bush's eight divisive years in the White House, an era that witnessed the Sept 11, 2001 terror attacks, the beginning of wars in Afghanistan and Iraq and an economic collapse not seen since the 1930s Great Depression.

Earlier, Obama used Monday's holiday in memory of civil rights giant Martin Luther King Jr. to exhort Americans to service and call on them to join him in taking responsibility for the country's future in a new age of accountability.

Obama's ascendancy marks a milestone once unthinkable in a nation that has struggled with racial issues since its founding and where segregation was practiced in many Southern states decades ago. It took place outside the US Capitol, which slaves helped build. Obama took oath on the same Bible used at the 1861 inauguration of Abraham Lincoln, whose Emancipation Proclamation ended slavery.

Braving icy temperatures and possible snow flurries, hundreds of thousands of people descended on the heavily guarded capital city on Tuesday for the first change of administrations since 2001.

Streets were filling up well before dawn and Washington subway cars were standing-room-only shortly after the trains began running at 4 am.

Obama's election electrified millions across the globe with the hope that the new American leader would be more inclusive and open to the needs of people and governments worldwide, more collaborative and more inclined to attack problems with diplomacy than with military power.

Tuesday's ceremony was the culmination of a remarkable ascent for the 47-year-old Democrat, who moves into the Oval Office as the nation's fourth youngest president. In less than five years, he rose from a little-known Illinois state lawmaker to the nation's highest office, persuading Americans that despite his relative inexperience, he could turn around the economy, end the Iraq war and restore US standing in the world.

A gifted, inspirational speaker, Obama has raised the hopes of millions as he outlined a new course for the United States. He has promised to emphasize diplomacy, seek global solutions to climate change, reject torture and shut down the Guantanamo Bay prison.

Obama's presidency puts Democrats firmly in charge of Washington. They will control both chambers of Congress and the White House for the first time since 1994.

Though the new president faces monumental challenges, but should face an extended honeymoon as he takes over from Bush, who leaves Washington as one of the nation's most unpopular and divisive presidents.

The 43rd president's approval ratings, which soared after Sept 11, plummeted over his handling of the Iraq war, his slow response to Hurricane Katrina and the economic meltdown.

Pre-inauguration polls showed Americans believed Obama is on track to succeed and express confidence the new president can turn the economy around. But Obama has cautioned that recovery needs time, and that things will get worse before they get better.

Culminating four days of celebration, Obama and Vice President-elect Joe Biden began the day with a traditional morning worship service at St. John's Episcopal Church, across Lafayette Park from the White House, and will end it with dancing and partying at 10 inaugural balls lasting deep into the night.

By custom, Obama and his wife, Michelle, were invited to the White House for coffee with Bush and his wife, Laura, followed by a shared ride in a heavily armored Cadillac limousine to the US Capitol for the transfer of power. On Monday, Vice President Dick Cheney pulled a muscle in his back. He was in a wheelchair for the inauguration.

Obama stepped forward on the West Front of the US Capitol to take the oath of office from Supreme Court Chief Justice John Roberts. The 35-word declaration has been uttered by every president since George Washington.

Obama - son of a Kansas-born white woman and a Kenyan born black father - decided to use his full name - Barack Hussein Obama - for the swearing-in.

To the dismay of liberals, Obama invited conservative evangelical pastor and gay marriage opponent Rick Warren to give the inaugural invocation.

More than 10,000 people from all 50 states - including bands and military units - assembled to follow Obama and Biden from the Capitol along the 1.5 mile (2.4-kilometer) inaugural parade route down Pennsylvania Ave, concluding at a bulletproof reviewing stand in front of the White House.

The inauguration drew almost 2 million people. Security was unprecedented as Washington braced for logistical headaches with major streets and bridges into the capital closed.u00a0

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