Nov. 5 (Bloomberg) -- Barack Obama said his election as the first African-American president of the United States sends a message that ``change has come'' to a troubled nation.

``If there is anyone out there who still doubts that America is a place where all things are possible, who still wonders if the dream of our founders is alive in our time, who still questions the power of our democracy, tonight is your answer,'' Obama, 47, told more than 125,000 cheering supporters who jammed into Chicago's Grant Park last night and early this morning to hear his victory speech.

Obama turned his attention today to his transition, meeting with advisers in Chicago and announcing the team that will guide the building of a new administration that takes power upon his inauguration on Jan. 20. He plans to remain in the city through the end of the week.

A wave of discontent with Republican rule and the nation's direction powered the Illinois senator to a sweeping victory over Republican rival John McCain. Obama won at least 349 electoral votes, far more than the 270 needed for a majority and the most for a winner since former President Bill Clinton got 379 electoral votes in 1996. Democrat Jimmy Carter won 297 electoral votes to win the presidency in 1976.

Vote Numbers

His 52.3 percent of the popular vote -- about 62.9 million ballots -- was the highest proportion since Republican George H. W. Bush's decisive win over Democrat Michael Dukakis in 1988. Obama's popular-vote percentage also is the highest for a Democrat since Lyndon B. Johnson's landslide victory in 1964 over another Arizona Republican, Senator Barry Goldwater.

McCain won 55.7 million, or 46.4 percent of ballots cast nationwide.

When all votes are tallied, it's likely the Obama-McCain contest spurred ``the largest turnout in 40 years,'' said Curtis Gans, director of the Center for the Study of the American Electorate at American University in Washington.

The final totals may not be known for six weeks as states finish counting and verifying the results, he said. For example, in California, the most populous state, 5 percent of precincts still haven't reported complete results.

The election should encourage ``those who've been told for so long by so many to be cynical and fearful and doubtful about what we can achieve to put their hands on the arc of history and bend it once more toward the hope of a better day,'' Obama said.

On the Streets

Americans spilled out on the streets in cities across the country to celebrate. Almost four hours after television networks called the race for Obama, people were still cheering and honking non-stop in Washington as thousands gathered by the White House, shouting Obama's name and his campaign slogan of ``Yes we can.'' Some simply chanted ``U-S-A.''

Obama last night took congratulatory phone calls from McCain and President George W. Bush, who vowed to ensure a ``smooth transition'' for the president-elect.

Arizona Senator McCain, 72, conceding the race in Phoenix, told his supporters that Obama won ``an historic election, and I recognize the special significance it has for African-Americans and the special pride that must be theirs tonight.'' He pledged to do ``all in my power'' to assist Obama and urged his backers ``to find ways to come together'' for the good of the country.

In a statement this morning, Bush said the election was important in the context of ``the struggle for civil rights.''

``No matter how they cast their ballot, all Americans can be proud of the history that was made yesterday,'' he said.

Majority in Congress

Obama's victory at the end of a 21-month quest, combined with Democratic victories that enhanced the party's majority in Congress, marked the end of an era of Republican dominance in Washington. He won a host of states that Bush had carried in 2000 and 2004, including Florida, Ohio, Colorado and New Mexico.

Obama also won Indiana and Virginia, which hadn't supported a Democratic presidential candidate since 1964.

The election put Democrats in firm control of the federal government for the first time since the early 1990s. That gives Obama an opportunity to turn his victory into a pivotal moment in the country's political history.

``He wants to be a transforming leader,'' said presidential historian James McGregor Burns in a Bloomberg radio interview. Such a leader, like Franklin Delano Roosevelt, ``knows how to proclaim great goals and summons the people to help him realize those goals,'' said Burns, who has written biographies of Roosevelt and other presidents.

Following Through

Having based his presidential bid on a promise of change in Washington and using that to create a new electoral coalition, Obama must now follow through or risk alienating those supporters, Burns said.

``He has made that so crucial to his campaign: change, change, change,'' Burns said. ``This man cannot escape now the responsibilities of trying to bring it about.''

To build a new administration, Obama named John Podesta, one-time chief of staff in President Bill Clinton's White House, confidante Valerie Jarrett, one of the most powerful women in Chicago, and his Senate chief of staff, Pete Rouse, to oversee the transition.

An advisory board that will help with transition planning includes former Clinton administration officials Carol Browner, William Daley and Federico Pena, as well as Arizona Governor Janet Napolitano, an early supporter.

Symbolism

The racial symbolism of Obama's campaign was never far from the surface. He formally declared his candidacy in February 2007 in Springfield, Illinois, evoking the spirit of Abraham Lincoln and his call for the nation to overcome the divisions of slavery. He wrapped up his campaign Monday night in Manassas, Virginia, site of two Confederate victories in the Civil War.

At the same time, Obama generally avoided overt discussions of racial issues. An exception was in March, when revelations of inflammatory remarks by his longtime pastor, Reverend Jeremiah Wright, led him to deliver a lengthy address on the subject.

In the nation's capital, thousands of supporters in a city that gave 93 percent of its votes to Obama poured through the streets and jammed into the pedestrian plaza in front of the White House to celebrate the victory and sing ``Hey Hey, Goodbye'' to Bush.

They chanted slogans, waved American flags and hoisted red, white and blue signs declaring, ``Yes we did,'' a play on Obama's slogan ``Yes, we can.''

``This is the logical place to be for such a momentous victory,'' said Lizzie Sam, 23, a Washington resident standing on the plaza on the north front of the White House, next to the U.S. Treasury building.

Similar Celebrations

Similar celebrations broke out in Seattle, San Francisco, New York and other cities.

Obama's victory represents a break with the razor-thin margins in the last two presidential elections.

In 2004, the election was too close to call until the next morning, when Democrat John Kerry conceded after concluding he couldn't surpass Bush's vote total in the decisive state of Ohio, which Obama won tonight.

Four years earlier, Bush's victory over Vice President Al Gore was in doubt for more than five weeks while Florida recounted its ballots. The Supreme Court finally halted the recount in December, and Gore capitulated. While Bush won the Electoral College by one vote with Florida, Gore had 543,000 more in the popular vote out of 105 million ballots cast.

Obama comes to the White House promising to pursue universal health-care coverage, alternative sources of energy and middle- class tax cuts. He faces daunting challenges: the worst financial crisis since the Great Depression, wars in Iraq and Afghanistan and the lingering threat of international terrorism.

Obama will have a Democratic House and Senate behind him after he takes the oath of office on Jan. 20. While not all of the races have been decided, the president-elect's party has clearly made gains in Congress.

To contact the reporters on this story: Ken Fireman in Washington at kfireman1@bloomberg.net; Kristin Jensen in Washington at kjensen@bloomberg.net

Last Updated: November 5, 2008 15:40 EST