Obama offered a call for reconciliation after a divisive election, but he also defended the freewheeling nature of politics and said big decisions "necessarily stir up passions."
Obama said he wants to meet with Republican rival Mitt Romney to discuss how they can work together and said he was willing to work with leaders of both parties to tackle upcoming challenges. Of his contest with Romney, he said they may have "battled fiercely, but it's only because we love this country deeply."
Obama made clear he had an agenda in mind, citing changes in the tax code, immigration reform and, as he put it, an America "that isn't threatened by the destructive power of a warming planet."
More immediately, he and Congress need to negotiate a new fiscal plan that avoids massive cuts in defense and other domestic spending and sharp across-the-board tax increases.
Obama has called for tax increases on households earning more than $250,000; House Speaker John Boehner has rejected any tax increases.
The president rolled to a second term over Romney, winning more than 300 electoral votes although he was only winning the national popular vote by a 50 percent to 49 percent margin.
"Tonight in this election, you, the American people, reminded us that while our road has been hard while our journey has been long we have picked ourselves up, we have fought our way back and we know in our hearts that for the United States of America, the best is yet to come," he told an ecstatic crowd of thousands in the cavernous McCormick Place convention center on Chicago's lakefront.
Obama appeared about two hours after he was declared the victor in his re-election bid and less than an hour after Romney offered a cordial concession.
The two men spoke by phone and Romney, in his own speech to supporters, said he prays "the president will be successful in guiding our nation."
Obama took the stage with first lady Michelle Obama and daughters Sasha and Malia. When he finished he was joined on stage by Vice President Joe Biden, whom Obama called "America's happy warrior," and Biden's extended family.
In his remarks he paid special tribute to his campaign team and his volunteers as the best "in the history of politics. The best. The best ever."
"Thank you for believing all the way through every hill, through every valley," he said. "You lifted me up the whole way."
Dozens of Obama and Biden staffers gathered on the floor next to the stage for the speeches.
Many stood with their arms around each other, some wiping away tears, as the president spoke.
