Obama's father, Barack Obama, Sr., was a teenager goatherd in rural Kenya; he won a scholarship to study in the United States and eventually became a senior economist in the Kenyan government. Obama's mother, S. Ann Dunham, grew up in Kansas, Texas, and Washington State before her family settled in Honolulu. In 1961 she and Barack Sr. met in a Russian language class at the University of Hawaii and married less than a year later.

When Obama was two years old, Barack Sr. left to study at Harvard University; shortly thereafter, in 1964, Ann and Barack Sr. divorced. Later Ann remarried, this time to another foreign student, Lolo Soetoro from Indonesia, with whom she had a second child, Maya. Obama lived for several years in Jakarta with his half sister, mother, and stepfather. While there, Obama attended both a government-run school where he received some instruction in Islam and a Catholic private school where he took part in Christian schooling.

He returned to Hawaii in 1971 and lived in a modest apartment, sometimes with his grandparents and sometimes with his mother.

Obama attended Occidental College in suburban Los Angeles for two years and then transferred to Columbia University in New York City, where in 1983 he received a bachelor's degree in political science. He returned to school three years later and graduated magna cum laude in 1991 from Harvard University's law school, where he was the first African American to serve as president of the Harvard Law Review. While a summer associate in 1989 at the Chicago law firm of Sidley Austin, Obama had met Chicago native Michelle Robinson, a young lawyer at the firm. The two married in 1992.

After receiving his law degree, Obama moved to Chicago and became active in the Democratic Party. He organized Project Vote, a drive that registered tens of thousands of African Americans on voting rolls and that is credited with helping Democrat Bill Clinton win Illinois and capture the presidency in 1992.

In 2004 he was elected to the U.S. Senate, defeating Republican Alan Keyes in the first U.S. Senate race in which the two leading candidates were African Americans.

In February 2007 he announced at the Old State Capitol in Springfield, Ill., where Abraham Lincoln had served as a state legislator, that he would seek the Democratic Party's presidential nomination in 2008.
On August 27 Obama became the first African American to be nominated for the presidency by either major party and went on to challenge Republican Sen. John McCain for the country's highest office. McCain criticized Obama, still a first-term senator, as being too inexperienced for the job. To counter, Obama selected Joe Biden, a veteran senator from Delaware who had a long resume of foreign policy expertise, to be his vice-presidential running mate.

The two candidates offered a stark ideological choice for voters. Obama called for a swift withdrawal of most combat forces from Iraq and a restructuring of tax policy that would bring more relief to lower- and middle-class voters, while McCain said the United States must wait for full victory in Iraq and charged that Obama's rhetoric was long on eloquence but short on substance. Just weeks before Election Day, Obama's campaign seized on the economic meltdown that had resulted from the catastrophic failure of U.S. banks and financial institutions in September, calling it a result of the Republican free-market-driven policies of the eight-year administration of George W. Bush.

Obama won the election, capturing nearly 53 percent of the popular vote and 365 electoral votes. Not only did he hold all the states that John Kerry had won in the 2004 election, but he also captured a number of states (e.g., Colorado, Florida, Nevada, Ohio, and Virginia) that the Republicans had carried in the previous two presidential elections. On election night tens of thousands gathered in Chicago's Grant Park to see Obama claim victory. Shortly after his win, Obama resigned from the Senate. On Jan. 20, 2009, hundreds of thousands turned out in Washington, D.C., to witness Obama taking the oath of office as president. Later that year he was awarded the Nobel Peace Prize.