Sandra Young, of Silver Spring, Md., said she was moved by the overlap between the two events.
"As an African-American, we think of the fact that we can do anything we set our minds to," said Young, who said she was in her 60s. "Being here, also, we think of the dream, and the dream is alive, and it's a real thing."
Rep. John Lewis, D-Ga., a veteran of the civil rights movement who knew King and knows Obama, said the symbolism was overwhelming.
"It is almost too much to believe that we would commemorate this year, the 150th anniversary of the Emancipation Proclamation, the 50th anniversary of the March on Washington," Lewis said. "I don't know what you'd call it, something about time and history and fate all coming together."
Lincoln issued the proclamation on Jan. 1, 1863, during the Civil War, declaring all slaves in states rebelling against the Union to be "forever free."
Vicki Crawford, director of Morehouse College's Martin Luther King Jr. Collection, said the inauguration falling in a year of civil rights milestones is a prime opportunity for the nation to re-examine its past and look ahead to the future.
"Obama is a part of the continuum of a history that began before Dr. Martin Luther King," she said. "It's a long history of struggle to make America the place it should be, to make real on the promise of democracy. This is a momentous time; 2013 is a crossroads."
Harris, the Columbia University professor, said that while King's moment in 1963 and Obama's in 2013 are evidence of how far the country has come despite persistent racial polarization, he would like to see Obama start to emphasize issues that were important to King.
"I would also hope that this won't be just a day of recognition but also that it will point in some direction in the second term that the president will begin to speak much more clearly and forcefully about the persistence of racial inequality in American life," he said.
Associated Press writers Eric Tucker in Washington and Kate Brumback in Atlanta contributed to this report.
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