CAPE GIRARDEAU, Mo. — There are moments in American history when the country knows that things have changed.
An enemy attacks. A leader is struck down. A new one emerges. Barriers are broken, in sports, in science, in popular culture. The shot heard round the world. Dred Scott. Appomattox. Black Friday. Pearl Harbor. Jackie Robinson. Salk vaccine. Brown v. Board of Education. Dallas. Martin. One small step for a man. Windows. 9-11.
And now, Barack Obama. The first African-American to secure the presidential nomination of a major political party.
It's been said so many times during the longest primary campaign in history that the fact has become background noise. But it's a profound development in a nation where the gulf between blacks and whites has been the defining divide since the first African slaves were unloaded at Jamestown in 1619.
"We've never gone this far before," said John Geer, a political scientist at Vanderbilt University in Nashville, Tenn.
It says as much about the country as it does about him. Maybe more.
The country is changing fast, and the history of race relations has accelerated in the last few decades, since the landmark court decisions and laws of the 1950s and 1960s opened doors at school and work. New faces there and at the ballpark and on the screen alarmed a generation unaccustomed to people different from themselves and shaped a younger one all but oblivious to skin-deep differences.
Yet resentment still simmers deep in some American hearts, and some whites harbor anger at affirmative action and school busing and say they'll never vote for an African-American for president.
America is also a place where whites and blacks still see life very differently.
All those fault lines are evident in Missouri, the heartland swing state that's witnessed so much racial history, from its 1820 admission to the Union as the country's northernmost slave state through epic school-desegregation fights that carried into the 1980s.
"My grandmother lived on a farm in the Boot Heel," said Cynthia Adams, 52, a white woman in the southeastern corner of the state, where Missouri rubs up against Arkansas, Kentucky and Tennessee.
"She had black farm workers. She would always say they're God's people, too. But she wouldn't let them in the house."
Adams remembers racial tensions from her childhood in small-town Missouri, and with some embarrassment recalls "some horrible things" she said about people.
Yet like a lot of people of her generation, her attitudes changed as she saw minorities on television, in sports, and got to know black people in school.
"I remember seeing commercials with black people and saying, this is so strange," she said. "I did have good friends who were African-American, though we didn't call them African-American then. I'm sure we all said offensive things as we joked around. But as I got older and had children and met people, I found everyone is a person deserving of respect."
"Where I grew up there was one black guy," said Jeb Morris, 34, a white utility lineman from Scott City, just south of Cape Girardeau. "Most people in my area seemed to wear cowboy hats or chew tobacco. I had no frame of reference growing up when it came to blacks.
"Then I joined the Marines and went to Quantico. I found a lot of racism in the military. A lot of white supremacists, racist Mexicans and blacks. That was a real eye-opener to me."
John Heisserer, 51, a white lawyer in Cape Girardeau, grew up in Chaffee, a small town nearby.
"There were zero African-Americans until the federal government built a housing project for the disadvantaged," he said. "I went to a Catholic school. Before I started attending, the KKK did parades in front of the school. But everything was fine, even after they built those homes."
Sandy Montgomery, 25, is one of two whites working at a St. Louis community development agency associated with the United Church of Christ, Barack Obama's church.
"It was an adjustment, I'll be honest," Montgomery said. "Our first big event that we had was a summer kickoff parade and picnic. . . . Some of the younger children . . . they want to play with your hair. . . .They're not used to hair like mine or skin like mine."
From attending picnics in black neighborhoods to dining in black restaurants with colleagues, Montgomery said, she's learned how much they have in common, and how much they differ.
"We definitely have different viewpoints based on our past and the way we grew up. I might see something in the media, I really think about it one way. They bring their own viewpoint, their own history, the way they grew up and the history they faced as young African-Americans and have a completely different take on what was said in the media."
Polls have found that blacks and whites see some things very differently.
A recent survey by Opinion Research for CNN and Essence Magazine, for example, found that 11 percent of whites think that discrimination remains a "very serious" problem, a fraction of the 43 percent of blacks who think so.
Another Opinion Research poll found that 64 percent of whites think that life has gotten better for blacks in the last 10 years; only 39 percent of blacks think so.
Take the way that people reacted to the comment by Obama's wife, Michelle, that his campaign made her proud of her country for the first time in her adult life.
"People just got offended," said Nina Thompson, 44, a black publicist from Ferguson, a mixed-race suburb of St. Louis.
"The reason they got offended is they didn't understand her. They didn't understand the racial discussion behind that. If you'd been a part of America, and your skin is brown, you've had certain experiences that do make you sometimes ashamed to be an American. She wasn't saying, 'I hate America,' she was saying, 'For the first time I really, really get it.' But they didn't understand that."
It takes communication to break down those barriers, Thompson said.
"When I moved from St. Louis to Jefferson City, which is like culture shock, the graphics guy was what I would call a redneck before I became more considerate," she said.
"He didn't have a clue; he didn't know anything about me. He didn't know how I wash my hair, he didn't know anything. I started bringing in Ebony Magazine, Essence Magazine and he said, 'I didn't even know these existed.' And so we grew to learn so much about each other."
Gerald Early, 55, a black African-American studies professor at Washington University in St. Louis, isn't so sure that communication is enough.
"I don't necessarily think that some kind of racial reconciliation is on the horizon because of this," Early said. "Being as old as I am and having seen race play out in this country as much as I have, my views are a little bit more sober than my daughters' views."
One daughter is a big Obama supporter, he said, who thinks his nomination and possible election herald a new age.
"She thinks this is a turning point. She thinks my generation, me and my wife, we're the old generation, civil rights, black power generation, all that kind of stuff, things have changed, people need to move on. Maybe they're right. I hope they're right. . . .
"I'm not convinced I'm holding on to a wrong paradigm yet. But my daughters feel we're kind of relics, you guys are '60s, '70s relics."
Old feelings can still be found on both sides, a sign that even as some things change, others remain the same.
"They were still lynching people in Springfield not too long ago," said Clara Vaughn, 55, a white retiree and the mother of two biracial children in Lee's Summit, a suburb of Kansas City.
"My daughter was recently pulled over in a little town in western Kansas," Vaughn said. "They asked her if she had weed in the car, wanted to know where she was going. She called me and said, 'I had my first black-over.' . . . There's still a huge racial divide."
A Democrat, Vaughn wasn't an Obama supporter and didn't vote for him in the Missouri primary, which he won narrowly. Still, she said, it's "progress" that a black man could succeed, especially in a state that's never elected a black person to statewide office.
Some Americans, though, are reluctant to change their minds, and not shy about saying so.
Sherry Anderson, 68, the white owner of an upholstering business in Laclede, a small town northeast of Kansas City, said she liked Obama because he was one of the few blacks who worked hard. The rest? "I have nothing against a black, except 99 percent of 'em don't work and I have to feed 'em," she said.
"I won't vote for a black guy. I don't want blacks running this country," said E.M. "Hot" Phillips, 80, a white retired storeowner from New Madrid.
"Race is an issue, sure," said Dub Prince, 62, a white barber in the small town of New Madrid who didn't like it when Obama said that some people clung to guns and God out of bitterness over their economic plight.
"I try to be open-minded, but I can't get around that comment. And I can't get around that Reverend Wright. I don't like how Obama is connected to someone who hates whites that much."
Riley Bock, 56, a white high school teacher whose family has lived in Missouri for 205 years, hears that often. "People will not accept a black president," he said. "They just won't do it. I listen to them in coffee shops, and it's not the man, it's the race. Some of it is holdover. Prejudice is hard to overcome."
That fact, however, doesn't diminish how far the country has come to the day when for the first time one of its major political parties has chosen an African-American to run for president.
"It says the country has taken a major step forward," said Julian Bond, a historian at the University of Virginia, a veteran of the civil rights movement and now the chairman of the NAACP. "It doesn't say that race has disappeared as an issue. But it is less an issue than it has been in the past."
(William Douglas and Matt Stearns contributed to this article.)