"Thank you," he said as Jackie Wilson's song "(Your Love Keeps Lifting Me) Higher and Higher" began playing. "I love you."
It may be nice to think that as a nation we have moved beyond race. But some observers say Obama faces serious questions of whether America is ready to elect an African-American president, or conversely whether he is not "black enough," as some African-American columnists have alleged.
And in that intersection of progress made and progress to come, the site of Obama's speech symbolizes not only hope for race relations in the U.S., but its myriad complications and ugly history.
On June 16, 1858, Lincoln -- then a U.S. Senate candidate -- delivered that famous anti-slavery speech to Republican delegates, paraphrasing Jesus by stating, "A house divided against itself cannot stand" to underline his belief that the U.S. "cannot endure, permanently half slave and half free." In that, the site is a place of optimism.
But Springfield is also the site of horrible race riots against blacks in 1908. Just a few blocks east from Obama's dais, a 56-year-old black barber named Scott Burton was lynched; an 84-year-old black shoemaker named William Donnegan was lynched a few blocks south. A false accusation of rape by a white woman against a black man had set a frenzied white mob upon first the town jail and then, with someone crying "Abe Lincoln brought them to Springfield and we will run them out," the black business district.
The Springfield Race Riot of 1908 not only resulted in the deaths of Burton and Donnega, but dozens of injuries, the destruction of hundreds of thousands of dollars worth of property and the displacement of hundreds of black families.
"What would their feelings be if they could see what is happening here today?" a columnist for the local Journal Register newspaper, Dave Bakke, wrote today. "What would those who were killed for the color of their skin think about a crowd that will come together today in the same place, but in a different mood and for such a different reason than that mob of 1908?"
Racial politics are an intriguing obstacle course for Obama. In 2000, Obama challenged U.S. Rep. Bobby Rush in the primary. Rush cleaned his clock, overwhelmingly winning in the predominantly African-American district. Obama, observers said, did not know how to appeal to black voters.
Even today, Clinton leads Obama among polls of African-American voters. Rush is now backing Obama, but tells the senator not to take the black vote for granted.
"I think it would be a mistake for Obama to neglect the black vote," Rush said. "I think he has to do some intensive work in the black community."
These are not new issues for the man born to a black Kenyan father and a white mother from Kansas.
In a 2003 interview with Jeff Berkowitz of "Public Affairs" on Chicago television, Obama said of his 2004 Senate race, "I'm rooted in the African-American community, but I'm not limited to it. And we are going to be competitive in every part of the state among every demographic."
Those dicey racial politics and the ultraliberal views Republicans say Obama held in his days at the Illinois capital are the issues that he will face again during this campaign.
For now, there is the ceremony of today's announcement. Soon enough, the ceremony will fade when candidate Obama moves on to the key early primary states, Iowa and New Hampshire, where his trip will coincide with that of his first serious opponent since Bobby Rush: Clinton.
ABC News' Greg McCown, Andy Fies and George Sanchez contributed to this report.