Washington - Illinois Senator Barack Obama and New York Senator Hillary Clinton fought for the Democratic presidential nomination for months. On Tuesday, Obama clinched the 2,118 delegates needed to secure the nomination, becoming the first African American to lead a major party in November general elections. Here is a look back at the key events:January 20, 2007: The former first lady officially announces her candidacy. Early polls showed her with a wide lead over her main competitors Barack Obama and John Edwards.
January 3, 2008: Obama wins the first primary in Iowa with 38 per cent of the vote. Clinton comes in third with 29 per cent behind Edwards, who won 30 per cent.
January 7: Clinton nearly cries at a campaign event, saying, "It's not easy," in response to a question about how she was feeling. The next day she surprisingly wins the New Hampshire primary with 39 per cent of the vote. Obama, who had been favoured to win, receives 37 per cent.
January 19: The former first lady prevails in the Nevada primary with 51 per cent of the vote compared with 45 per cent for Obama.
January 26: South Carolina delivers a clear win for Obama, with 55 per cent to 27 per cent for Clinton.
February 5: On Super Tuesday, Obama wins in 13 states, while Clinton takes nine of more than 20 states holding primaries, including California.
February 10: After Clinton loses to Obama in Nebraska, Louisiana, Maine and in the state of Washington, her campaign manager Patti Solis Doyle steps down. She is succeeded by Maggie Williams who was Clinton's chief of staff during her years as first lady.
February 12: Obama wins in Virginia, Maryland and the capital city of Washington. For the first time in the campaign he is ahead of Clinton in the number of delegates to the Democratic Party convention.
February 19: With victories in Wisconsin and Hawaii, Obama succeeds in winning 10 primaries in a row. He outclasses Clinton with double-digit percentage point winning margins in each state.
March 4: Clinton celebrates a comeback, winning the primaries in Ohio, Texas and Rhode Island. Obama wins in Vermont and a concurrent caucus in Texas. Clinton indicates she could imagine Obama as vice president.
March 6: Campaign finance figures show Obama received 55 million dollars in donations in February, Clinton 35 million dollars.
April 22: The large eastern state of Pennsylvania hands Clinton a clear victory. She receives 55 per cent of the vote to her rival's 45.
May 6: Obama strengthens his chances with a win in North Carolina, where he receives 56 per cent of the vote to Clinton's 42. In Indiana, Clinton wins a razor-thin victory, finishing two percentage points ahead of Obama.
May 12: Obama takes the lead in super delegates, the party leaders and officials who vote independently of the elections. At the beginning of the primaries, Clinton led in the super delegate count by more than 100. Her campaign debts, meanwhile, amount to 20 million dollars, according to US media reports.
May 13: After a clear victory in West Virginia, the senator stresses that she's not considering ending her candidacy.
May 14: After months of hesitation Edwards, who quit the campaign at the end of January, endorses Obama.
May 31: Party officials agree to give Florida and Michigan a voice in the US presidential nomination process despite their disputed January elections, but with only half their normal voting power in a significant blow to the dwindling ambitions of Hillary Clinton for the White House. She had done well in the states that were punished for holding their votes earlier than party rules allowed.
June 1: Clinton wins the territory of Puerto Rico.
June 3: Obama secures the 2,118 delegates needed to become the Democratic nominee, becoming the first African American to represent a major party in November presidential elections. Clinton does not concede defeat.
