Americans elected Democrat Barack Obama as their first black president, in a transformational election which will reshape US politics and reposition the United States on the world stage.
Obama, 47, will be inaugurated the 44th US president on January 20, 2009, and inherit an economy mired in the worst financial crisis since the 1930s, two wars in Afghanistan and Iraq and a nuclear showdown with Iran.
Television networks projected his victory over Republican John McCain after Senator Obama solidified traditional Democratic states and cut deep into the Republican territory which his rival needed to control to win the White House.
Obama's historic inauguration will complete a stunning ascent to the pinnacle of US and global politics from national obscurity just four years ago and close an eight year era of turbulence under President George W. Bush.
He will take office with Democrats holding a monopoly in power in Washington, after an epochal election which sparked a rare generational and political realignment and finally snuffed out an era of Republican control.
Obama is promising to renew bruised ties with US allies, and to engage some of the most fierce US foes like Iran and North Korea. He has vowed to pass tackle climate change and provide health care to all Americans.
His presidency also marks a stunning cultural shift, with Obama, the son of Kenyan father and white mother from Kansas, the first African American president of a nation still riven by racial divides.
When he launched his campaign on a chilly day in Illinois in February 2007, Obama forged a mantra of change which powered him throughout the longest, most costly US presidential campaign in history.
With a stunning grassroots political movement, powered by massive multi-million dollar fundraising, Obama first beat Hillary Clinton, and the Democratic Party's then preeminent political machine.
Obama strode towards victory on Tuesday by capturing the states of Pennsylvania, the key battleground which McCain needed to win to keep his long-shot hopes of victory alive.
In a sweet moment for Democrats, he also seized the midwestern battleground of Ohio and captured New Mexico and Iowa, two states won by Bush in 2004 to close out McCain's possible route towards the White House.
Obama had led national and battleground polls and had capitalized on the fear of Americans pitched into the deep financial crisis, especially as he appeared to be presidential in a string of debates.
McCain had argued that Obama was too inexperienced to be US commander in chief and would pursue "socialist" redistribution policies that would leave the economy mired in recession.
McCain, 72, an Arizona senator, would have been the oldest man ever inaugurated for a first term in the White House.
