WASHINGTON (AP) – Democratic Senator Barack Obama took the initial step yesterday towards a presidential campaign that could make him the first black American to occupy the White House.

Obama filed papers creating a presidential exploratory committee, which he announced on his website, www.barackobama.com. He said he would announce more about his plans in his home state of Illinois on February 10.

“I certainly didn’t expect to find myself in this position a year ago,” Obama said in a video posting. “I’ve been struck by how hungry we all are for a different kind of politics. So I’ve spent some time thinking about how I could best advance the cause of change and progress that we so desperately need.”

Obama, 45, whose only national experience is just over two years as a US senator, is the most inexperienced candidate considering a run for the Democratic nomination. Still, he is considered a prime contender in a race where Senator Hillary Rodham Clinton, former President Bill Clinton’s wife, is widely expected to run and is considered the front-runner.

Obama quickly rose to national prominence after a stirring keynote speech at the 2004 Democratic National Convention, which nominated John Kerry and John Edwards to run against the Republican president, George W Bush, and vice-president Dick Cheney.

The Constitution denies Bush the opportunity to seek a third term, and Cheney repeatedly has ruled out a run for the presidency.

There is little question about Obama’s star status in the Democratic Party. During last year’s congressional election campaign, he was not among the 33 senators running for re-election but ranked among the most sought-after campaigners for his Democratic colleagues and members of the House of Representatives who were running.

He, however, remains an unknown quantity to many Americans, despite two best-selling autobiographies – The Audacity of Hope: Thoughts on Reclaiming the American Dream and Dreams from My Father: A Story of Race and Inheritance – that have helped fill in the gaps.

His appeal on the stump, his unique background, his opposition to the Iraq war and the fact that he is a fresh face set him apart in a competitive race for the presidency next year.

Born in Hawaii in 1961, Obama is the son of a Kenyan who herded goats as a child with his father, a domestic servant to Kenya’s British rulers. Barack Obama Snr left Kenya on an academic scholarship and met and married Ann Dunham, born in the Mid-western state of Kansas, while they were students at the University of Hawaii.

Obama is a graduate of Columbia University and Harvard Law School, where he was the first black student elected editor of the Harvard Law Review. He settled in Chicago, where he joined a law firm and taught constitutional law at the University of Chicago’s Law School. He also helped local churches establish job training programmes for residents of poor neighbourhoods and organised a major voter registration drive in the 1992 election.

While working at a corporate law firm in the summer of 1989, Obama met Michelle Robinson, then an associate attorney at the firm. They married in 1992, and have two daughters, Malia and Sasha.

In 1996, he was elected to the Illinois state Senate, where he earned a reputation as a consensus-building Democrat who was strongly liberal on social and economic issues.

He supported homosexual rights, abortion rights, gun control, universal health care and tax breaks for the poor, but set himself apart from others by working with opponents to resolve policy disagreements and refusing to become a rubber stamp for his allies.

The retirement of Republican Senator Peter Fitzgerald of Illinois in 2004 drew a raft of candidates to the Democratic primary, but Obama easily outdistanced his competitors. He was virtually assured of victory in the general election when the designated Republican candidate was forced from the race by scandal late in the election. His replacement, conservative gadfly Alan Keyes, who also is black, took less than 30 per cent of the vote.