Senator Barack Obama cast his ballot at his Chicago neighbourhood's precinct of Hyde Park.

"I voted," Mr Obama told onlookers as he held up the validation slip he had been handed.

The 47-year-old Illinois senator was accompanied by his wife Michelle and their two young daughters Malia, 10, and Sasha, seven.

In his final rally in Virginia, which has not voted for a Democratic presidential nominee in 44 years, he told almost 100,000 people: "I'm feeling kind of fired up. I'm feeling like I'm ready to go.

"At this defining moment in history, Virginia, you can give this country the change it needs."

Mr Obama continued: "Along the way in talking with you about your own lives, you've enriched my life. You have moved me again and again.

"You have inspired me. I've come away with an unyielding belief that if we only had a government that was responsible as all of you, as compassionate as the American people, then there's no obstacle we can't overcome.

"There's no destiny that we cannot fulfill."

Obama campaign manager David Plouffe said he was confident that new voters and young voters would fuel an enormous turnout to benefit the Democrat.

Mr Plouffe said: "We just want to make sure people turn out. We think we have enough votes around the country."

Americans will decide between Mr Obama, an inexperienced senator with a powerful message of change and hope for the nation, and former Vietnam prisoner of war Mr McCain, who, at 72, would be the oldest first-term president with 26 years of experience in the US Congress.

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