"I have called Senator Obama to congratulate him and wish him well," Clinton wrote in a written statement.
"We now turn our attention to the millions of Americans who will make their voices heard in Florida and the twenty-two states as well as American Samoa who will vote on February 5th," the Clinton statement read. This is the second win of the nomination battle for Obama, who won the Iowa caucuses earlier this month, but this is his first win in a state with a sizable African-American population.
Women and African Americans, courted heavily by the candidates, turned out in very large numbers to vote in what became a bitter Democratic primary marked by rhetoric about race and gender.
Exit poll results indicate just over half of Democratic primary voters were black this year -- what may be the highest turnout among African-Americans in any Democratic presidential primary at least since 1984, reports ABC News' Gary Langer. Women accounted for six in 10 voters, similar to their 57 percent turnout rate in 2004.
Obama went into the first Democratic Southern contest the clear favorite, buoyed by support from black voters.
African American Voters Boost Obama
Sen. Hillary Clinton started out strong in the state, but began to trail Obama in December. In recent weeks her campaign has tried to lower expectations, positioning her as the underdog in the race, and largely leaving her husband, former President Bill Clinton, to campaign for her in the Palmetto State.
Yet to win any primary contest so far, John Edwards lost again tonight, another crushing blow to the former senator, who was born in South Carolina and won the state in 2004. Edwards suggested this week that even if he lost his home state, he intended to continue campaigning into Super-Duper Tuesday, Feb.5.
But in a campaign dominated by talk of race, South Carolinians went into the polls with the economy on their minds; just over half called it the most important issue in their vote. South Carolina has the fourth-highest unemployment rate in the nation, and has lost more than 90,000 manufacturing jobs over the last decade.
Obama is expected to address supporters soon tonight in Columbia. This afternoon he played a pickup game of basketball at the Columbia YMCA with some of his staffers. Earlier in the day, Obama visited a predominantly African American church and college, and greeted brunch-goers at Harper's Restaurant in Columbia, posing for photographs and thanking people for their vote.
Obama: Media Focused 'Maniacally' on Race
"Here in South Carolina there is a sizable African-American population. Not surprisingly, we're doing well there. I'm sure they're taking pride in my candidacy," Obama told ABC News' Kate Snow on Saturday's "Good Morning America Weekend" edition.
Early on, the Obama campaign sought out African-Americans, employing a large staff in the state and organizing in churches, beauty parlors and barber shops. The Clinton campaign, too, fought hard for black women voters, who tend to turn out reliably at the polls.
But Obama complained the media's focus on race has been excessive.
"The press has been very focused, almost maniacally, on the issue of race here in South Carolina," Obama told ABC News' Kate Snow. "But as we move forward after this contest, I'm very confident that we are going to continue to build the kind of coalitions that we've been seeing all across the country."
The junior senator from Illinois dismissed the notion he has been marginalized, in the words of Associated Press writer Ron Fournier, as "the black candidate, by the Clinton machine."
"I think it'd be hard to argue that I have been marginalized, when I won Iowa, which was 94 percent white. We were almost tied in New Hampshire, a state that has an all-white population. And in Nevada, I was able to win, actually, the biggest votes, uh, margins, in those northern areas that are predominantly white, rural, conservative areas," Obama said.
Former President Bill Clinton made headlines this week when he chastised CNN reporter Jessica Yellin for challenging him about comments he made about race and gender.
Clinton Camp Plays Expectations Game
Hillary Clinton boarded a plane in Columbia S.C. tonight for Nashville, Tennessee where she will speak to supporters at 8:30pmET.
Campaigning Saturday morning in Columbia with her daughter, Chelsea, Hillary Clinton popped into a Shoney's restaurant and urged people to vote.
"I am just hoping for a good day. I am just hoping for a big turn out," she said, reports ABC News' Eloise Harper.
Sitting down beside an 8-year-old boy named Messiah, who was playing a video game, Clinton leaned in and said, "So this guy, what's he doing?"
Looking at the game, he said, "Beatin' up the evil people." Clinton paused and said, "Can I have him come with me?"
Nearby, Bill Clinton ate grits and eggs with supporters of his wife at Bert's Grill and Diner, and visited a voting station down the road, reports ABC News' Sarah Amos.
Race Shifts to Florida
Behind the scenes, Clinton's campaign sent out a memo to reporters that attempted to minimize the impact of the South Carolina contest.
"Regardless of today's outcome, the race quickly shifts to Florida, where hundreds of thousands of Democrats will turn out to vote Tuesday," wrote Clinton Communications Director Howard Wolfson.
In a sign of how bad the blood is between the two campaigns, Obama's spokesman Bill Burton quickly sent a memo of his own.
"It should not be surprising given recent events that the Clinton campaign would in one breath say the election is about winning delegates and then tout their success in states that don't award any delegates in the next breath," Burton wrote.
That type of back-and-forth bickering between the Obama and Clinton campaigns has allowed Edwards, who has moved up in the polls in recent weeks, to argue that he is the only "grown-up" in the race, running ads showing his rivals attacking one another at Monday night's debate.
"Vote for somebody who's actually focused on the problems that you're faced with, from jobs to health care to ending the war in Iraq, as opposed to two candidates who are spending all their time and energy tearing each other down. I'm about building South Carolina up, not about tearing people down, not about tearing politicians down," Edwards said Saturday, campaigning in Charleston.
A loss in his home state could drive a stake through the former senator's presidential ambitions, but Edwards told ABC News' David Muir Friday he's going to continue to fight, even if he comes in third.
Edwards is expected to stay in the race at least until the Super-Duper Feb. 5 contests, because his advisers believe he could play kingmaker if his two rivals end up short on delegates.
On primary day the Clinton campaign launched a series of anti-Edwards robotic calls in South Carolina, reminding voters that Edwards once worked for a hedge fund that, the call maintained, has been "profiting" from subprime lending and home foreclosures.
"You should also know that John Edwards made nearly a half a million dollars working for a Wall Street investment fund. A fund that's been profiting on foreclosing on the homes of families, including 100 homes right here in South Carolina. Can you trust John Edwards? This call is paid for by the Hillary Clinton for President Campaign."
In a race that has increasingly become a delegate war leading up to the Super-Duper Feb.5 primaries and caucuses, 45 delegates are up for grabs in the state.
A win tonight gives Obama a boost, and some much needed momentum before Tuesday's Florida primary and before voters in more than 20 states have their say Feb. 5.
ABC News' Gary Langer, Kate Snow, David Muir, Eloise Harper, Sarah Amos, Sunlen Miller, Raelyn Johnson and Karen Travers contributed reporting.