The road to the White House -- a time line

February '07

2/10/07 >>On a cold Illinois day nearly two years ago, Barack Obama, pictured with his wife, Michelle, announced his candidacy for U.S. president on the steps of the Illinois Old State Capitol. He was the last Democrat to announce his campaign. Democrats Hillary Rodham Clinton, John Edwards, Joe Biden, Christopher Dodd, Mike Gravel, Dennis Kucinich, Bill Richardson and Tom Vilsack were already in the race. Republicans Sam Brownback, Rudy Giuliani, Mike Huckabee and Duncan Hunter were in the race on the GOP side.

2/13/07 >>Mitt Romney declares his candidacy for the Republican nomination.

2/23/07 >>Tom Vilsack withdraws from the race.

March '07

3/12/07 >>Rep. Ron Paul (Texas) announces his candidacy for the Republican nomination.

3/29/07 >>Civil rights leader, politician and minister Jesse Jackson endorses Obama. "He has my vote," the Rev. Jackson told The Associated Press in a telephone interview. His son, Rep. Jesse Jackson Jr. of Illinois, had already endorsed Obama.

April '07

4/1/07 >>Tommy Thompson announces his candidacy for the Republican nomination.

4/2/07 >>Rep. Tom Tancredo (Colo.) announces his candidacy for the Republican nomination.

4/25/07 >>Arizona Sen. John McCain announces his candidacy for the Republican nomination.

4/26/07 >>Former Virginia Gov. Jim Gilmore announces his candidacy for the Republican nomination.

May '07

5/3/07 >>The Secret Service begins guarding Obama -- 18 months before the general election and the earliest a presidential candidate has ever been provided protection.

June '07

6/07 >>The "Obama Girl," Amber Lee Ettinger becomes an overnight celebrity when the music video "I Got a Crush on Obama," hits YouTube.

6/30/07 >>Barack Obama outraises Hillary Clinton in the second quarter of 2007 with a $31 million haul. Clinton raised $27 million during that period. Rudy Giuliani was the Republican fundraising winner; his campaign announced receipts of $17 million in the second quarter, $3 million more than the $14 million raised by Mitt Romney, and far ahead of John McCain, who was a distant third at $11 million.

June '07

Jim Gilmore withdraws from consideration for the GOP's nomination.

August '07

8/5/07 >>Republican contenders debate in Des Moines, Iowa.

8/9/07 >>The Democratic hopefuls also hold a roundtable in Los Angeles.

8/12/07 >>Tommy Thompson withdraws from the race.

September '07

9/5/07 >>Former U.S. Sen. Fred Thompson, left, announces that he is formally joining the 2008 White House race, during the taping of "The Tonight Show with Jay Leno".

9/14/07 >>Alan Keyes announces his candidacy for the Republican nomination.

9/17/07 >>Hillary Clinton announces a proposal for a universal health care plan.

October '07

10/2/07 >>Hillary Clinton raised $22 million for her presidential primary campaign this summer, outpacing all other candidates so far with her best three-month showing of the year. Her total fundraising of nearly $80 million for the 2008 presidential race puts her on par with her chief Democratic fundraising rival, Barack Obama. Obama reported raising at least $19 million from July through September for the primaries.

10/18/07 >>Sam Brownback withdrew from the race and later endorsed John McCain.

November '07

11/22/07 >> New Hampshire set its U.S. presidential primary for Jan. 8, 2008, ending months of speculation.

December '07

12/20/07 >> Tom Tancredo withdraws from the race and endorses Mitt Romney.