Barack Obama was on course to make history tonight by becoming the first black president of the United States.

Millions of Americans today joined long queues around the country as they prepared to vote for a new era in US politics.

A record high turnout of 130 million people were expected to vote for the 44th president of the United States, with 30 million having already cast their ballots.

Front runner Obama, who appeared to wipe tears from his cheeks on the campaign trail yesterday following the death of his grandmother, joined the nation's earliest voters today in Chicago.

His Republican rival John McCain plans to vote later in Arizona.

After one of the longest and most expensive presidential elections in history the nation will elect either its first black president or its first female vice president, Republican Sarah Palin.

Both candidates were planning last-minute campaign stops to try to woo any Americans still undecided after a hard-fought almost two-year campaign which is estimated to have cost £1.5 billion.

"I voted,’’ Mr Obama told reporters as he held up the validation slip he was handed after turning in a ballot at his Chicago neighbourhood's precinct of Hyde Park.

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

He will end his campaign late tonight at a rally in Chicago where an estimated one million people are expected.

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.’’