Americans choose Tuesday between Barack Obama and John McCain in a epochal election which could enshrine their first black president, herald a new era of Democratic dominance and transform US foreign policy.
History's longest, most costly campaign ends with Democrat Obama leading national and battleground polls, and his Republican foe seeking a shock comeback.
After eight years of President George W Bush, Democrats are seeking to expand majorities in Congress and to take a stranglehold on power for the first time since the early 1990s.
In the eye of the worst financial storm since the 1930s and with US troops waging two foreign wars, both Obama and McCain have vowed to restore the frayed self confidence of the world's lone superpower.
"We can choose hope over fear, unity over division; the promise of change over the power of the status quo," said Obama, 47, who's election would transfer the leadership baton to a new generation.
"If you give me your vote on Tuesday, we won't just win this election -- together, we will change this country and change the world," the Democrat told Americans in a radio address yesterday.
He vows to repair ties with US allies, to open talks with US foes like Iran and Cuba, bring troops home from Iraq and refocus on the Afghan war.
McCain, leveraging his Vietnam War heroism and decades of experience in Washington, would be the oldest president, at 72, inaugurated for a first term.
He has lambasted Obama for "socialist" tax policies, and like the Democrat's vanquished primary foe Hillary Clinton, argues his rival is unprepared for an age of global turmoil.