On a freezing day in February 2007, the first-term U.S. senator announced his candidacy for president outside the Old State Capitol in Springfield, Ill., saying he could not wait until politics "boil the hope out of him." His best-selling third book was called "The Audacity of Hope: Thoughts on Reclaiming the American Dream."
He said his late mother, Stanley Ann Dunham, who died of cancer at 53, and his grandmother, Madelyn Payne Dunham, 86, taught him how to dream and value hard work, and were the guiding forces of his life.
Obama described his birth at Kapi'olani Medical Center for Women and Children in Hawaii Aug. 4, 1961, to a young white woman from Kansas and a father of Luo ethnicity from Nyanza province in Kenya, as an "all-America" story transcending orthodox racial stereotypes and experience. Even his name -- Barack means "one who is blessed" in Swahili -- seemed to signal great things for Obama.
After a scholastic career that included being the first black president of the Harvard Law Review, Obama worked as a community organizer in Chicago. He won a seat in the Illinois Senate in 1996 and held it until he ran for the U.S. Senate in 2004.
It was that year he burst upon the national political scene with a stirring keynote speech at the Democratic National Convention. That fall he won his Senate seat with more than 70 percent of the vote.
Before launching his political career, Obama joined the Chicago law firm of Miner, Barnhill & Galland to practice civil rights law. He had met his future wife, Michelle Robinson, in 1989 when he was a summer intern at Sidley & Austin, a corporate law firm. They married in 1992 and have two daughters, Malia, 9, and Sasha, 7.
(This item was corrected July 8, 2009, to fix the name of the hospital where Obama was born. The original item incorrectly identified the facility as Queen's Hospital, an error made by the writer.)