Barack Obama, the Illinois Democrat who built a campaign and a movement around the promise of change, won a resounding victory over Republican John McCain Tuesday night, becoming the first black president in U.S. history.
Choosing a steady 47-year-old lawyer and former community organizer to guide the nation, voters looked past Obama's relative lack of national experience to end eight years of Republican leadership amid a once-in-a-century economic crisis and protracted foreign wars.
Hundreds of thousands of supporters gathered in Grant Park in Chicago, which Obama represented in the Illinois Legislature just 46 months ago, as the Democrat was declared the winner about 11 p.m. Eastern time.
Obama said that his victory reaffirmed that America remains a place "where all things are possible."
"It's been a long time coming, but tonight, because of what we did on this date, in this election, at this defining moment, change has come to America," he said.
Celebrations erupted in New York, Washington, Baltimore, Atlanta and other cities.
The son of a mother from Kansas and a father from Kenya, Obama becomes the first U.S. senator to be elected president since John F. Kennedy in 1960. The 44th president will take office at a time of daunting challenges, amid an economic crisis that threatens to overwhelm his promises to spend on education, health care and energy.
To enact his programs, he will rely on a Congress with Democratic majorities that grew after Tuesday's voting. Democrats picked up at least five seats in the Senate and at least 14 in the House of Representatives.
Obama carried Ohio, Virginia, Colorado, Florida and New Mexico, states that went to President Bush four years ago, and won electoral vote-rich states that had been trending his way, including Pennsylvania and Minnesota.
In a year when voters seemed to crave a clean break from the Washington status quo, McCain, a former prisoner of war in Vietnam, never shook the burden of representing the party of Bush. Six of 10 voters in Maryland said a McCain administration would continue Bush's policies, and three in four said the country was on the wrong track, according to a Maryland exit poll.
McCain campaigned as a maverick willing to buck his party on campaign finance, immigration and tax cuts. But his three decades of experience in Washington -- he would have become the oldest man elected to a first term as president -- were never a sufficient asset in the contest.
"We have come to the end of a long journey. The American people have spoken, and they have spoken clearly," McCain said Tuesday night.
He credited Obama with "inspiring the hopes" of millions of Americans.
"This is an historic election, and I recognize the special significance it has for African-Americans and for the special pride that must be theirs tonight," McCain said in Phoenix.
Obama built a national advantage as the financial crisis unfolded in late September, with voters saying they perceived Obama as more responsive than his rival to the urgency of the housing collapse and credit crunch.
Marylanders voted for Obama by a margin of more than 2-to-1, delivering him, as expected, one of his strongest showings of the day.
Half the voters in Maryland said they were "excited" by the prospect of an Obama administration, compared with just one in 10 who expressed the same sentiment about McCain, according to the exit poll conducted by Edison Media Research for The Baltimore Sun and WYPR.
A Democratic administration in Washington, the governor said, could help the state on health care and other issues.
Obama and McCain were the last survivors of the longest and most expensive campaign presidential campaign ever waged, with $1.5 billion raised by candidates through the middle of October, according to the Federal Election Commission.
Obama built an organization that has changed the face of electoral politics. Reversing a promise, he rejected public campaign financing and raised $639. million, nearly half in contributions of $200 or less, from 3.2 million donors. That meant that roughly one in 20 people who voted for Obama had given to his campaign.
By agreeing to the public system, McCain was limited to $85 million for the general election, and raised $335. million in all.
Embracing new technologies, the Obama campaign built an unprecedented database of volunteers, connected through the Internet and spurred to action through e-mail and social networks.
In Maryland, clusters of Obama volunteers gathered every weekend at meeting points and headed to Virginia and Pennsylvania, competitive states where their enthusiasm could have more impact.
The excitement for his campaign, particularly among African-Americans, led to long lines at polling places in Maryland and other states with large minority populations.
At Woodmoor Elementary School in Woodlawn, voters brought collapsible chairs, snacks and even a battery-operated TV in a line that snaked out to the school's driveway and around the building.
"I came to make history and vote for Obama," said Misty Janey, 35, a registered Democrat who works as a cocktail waitress at the new Hilton in downtown Baltimore. "Make history and change history."
Her 4-year-old niece, Amya Watson, chimed in, "This is history. Obama, I love you."
Pushing the button for Obama "felt wonderful," Janey said. "I wanted to cry."
Janey's sister-in-law, Marquita Watson, 25, a massage therapist who is five months pregnant, brought her daughter because "I want her to be a part of history."
As Obama reached for states that had voted Republican in the past, he looked to make good on a promise to reach across party lines to bridge divides, one of the themes of his 2004 speech at the Democratic National Convention, which thrust him to national prominence.
Axelrod and other top advisers ran a largely mistake-free campaign, demonstrating exemplary organizing skills in Iowa and other caucus states as they pulled ahead of their main primary rival, Sen. Hillary Clinton, as the primaries dragged on.
Obama suffered setbacks, overcoming negative publicity over incendiary remarks of his pastor, the Rev. Jeremiah A. Wright Jr. To rebut charges that he belonged to a church that was out of the mainstream, Obama delivered a definitive speech on race relations that changed the tenor of the discussion.
He called Pennsylvania voters suffering from the economic downturn "bitter," and a sidebar comment to a worker in Ohio who came to be known as Joe the Plumber was pounced on by McCain as evidence that Obama possessed socialist inclinations because he wanted to "spread the wealth."
But Obama was never gravely hurt by his few missteps, his standing improving through his performance in debates and his selection of Delaware Sen. Joe Biden, a Washington veteran, as his running mate.
"The way he handled the economic pressures, what he said, and the calm way he reacted and the leadership that he exerted, I think really turned a lot of voters around," Gov. Ed Rendell of Pennsylvania, a former Clinton supporter, said Tuesday night.
Cardin, the Maryland Democrat, predicted that Obama would pass initiatives on housing, energy independence and some health care ideas in his first 100 days, the traditional period when a new president gets the most done, but that some of his biggest ideas "will have to be tempered" by budget realities.
Baltimore Sun reporters Jennifer McMenamin and Gadi Dechter contributed to this article.