The first black American to be a major party's candidate, he pipped Mrs Hillary Clinton to the finish line on the last day of the party's longest-ever primary race.

Mrs Clinton, 60, a two-term senator from New York and former first lady, insisted to the very end that she was the better candidate for America's top job.

Just a year ago, she seemed the inevitable choice, on track to creating history herself as the first woman candidate for president.

By contrast, Mr Obama, the son of a Kenyan farmer and white American mother, was a first-term senator from Illinois.

Their race lasted nearly six months, marked by twists and turns as one, then the other, looked likely to emerge winner.

Their neck-and-neck contest ran all the way to the very last two states on Tuesday and ended with him winning in Montana, while she took South Dakota.

Finally, with an eleventh-hour surge of support from party delegates, it was Mr Obama who secured the critical 2,118 tally of delegates needed for the nomination.

He is expected to be formally nominated at the party's national convention in August, and will face off against Republican John McCain, 71, in November.

Cheered by thousands of supporters in St Paul, Minnesota, late Tuesday, he said: 'Tonight we mark the end of one historic journey with the beginning of another - a journey that will bring a new and better day to America.'

Yet Mrs Clinton was not about to concede defeat. In fact, addressing her supporters, she sounded almost like she had won.

'I want the 18 million Americans who voted for me to be respected,' she said to loud cheers.

Political analysts read that as pressure on Mr Obama to select her as his running mate - a prospect bringing pluses and minuses he must weigh in the days ahead.

bhagya@sph.com.sg

MORE STORIES

SHE'S NOT CONCEDING YET

'This is a long campaign and I will be making no decisions tonight.'

MRS HILLARY CLINTON