"I have a dream that one day down in Alabama ... little black boys and black girls will be able to join hands with little white boys and white girls as sisters and brothers," the civil rights leader said on Aug. 28, 1963.
As the United States marks the 50th anniversary of King's "I Have A Dream" speech, there may be no better place to measure the progress that followed his historic call than Birmingham, Alabama.
This city, once a symbol of segregated bus seating and water fountains, is hallowed ground in civil rights history. It was here where children marching for equal rights were jailed, where protesters were attacked by snarling police dogs and battered by high-pressure fire hoses. It was here where four little girls in their Sunday finest were killed when dynamite planted by Ku Klux Klan members ripped through their church.
That was the Birmingham of the past. The city that King condemned for its "ugly record of brutality." The city where he wrote his impassioned "Letter from a Birmingham Jail," declaring the "moral responsibility to disobey unjust laws." The city where the movement came together, found its voice and set the stage for landmark civil rights legislation.
So has King's dream of equality been realized here and has Birmingham moved beyond its troubled past?
In many ways, the answer is yes, the city has changed in ways that once seemed unthinkable.
The airport is named after a fearless civil rights champion, the late Rev. Fred Shuttlesworth. Black mayors have occupied City Hall since 1979, in part because many white residents migrated to the suburbs, a familiar pattern in urban America. Today, nearly 75 percent of the population is black.
The city forthrightly commemorates the shameful events of the 1960s. Amid the flowers in Kelly Ingram Park, there are stark reminders of the ugly clashes. There's one sculpture of a young protester, his arms stretched back, as a policeman grabs him with one hand and holds a lunging German shepherd in the other. There is also a statue commemorating King.
Yet while the overt racism of the 1960s has long disappeared, the issue has not.
Legal and social barriers that barred black people from schools and jobs fell long ago, but economic disparity persists. Blacks and whites work together and dine side by side in restaurants, but usually don't mingle after 5 p.m.
Glennon Threatt was a 7-year-old in Birmingham when King announced his vision of a color-blind society during the March on Washington.
Not long afterward, Threatt was among three black gifted students enrolled in a white elementary school. He was spat on, beat up and called a racial slur.
As a young man, he boarded a bus on his way to Princeton University, vowing never to return to Birmingham.
He would change his mind. After moving back in 1997, Threatt joined an established law firm - something that would have been unimaginable 50 years earlier. Both he and the city had changed, he says.
Now 57, Threatt occasionally runs into an old schoolmate - a bank vice president - who had been among his tormenters. They always have a pleasant chat. But he never forgets.
"I like him," he says. "I don't think he's a racist. He was a kid caught up in a social situation like I was. .... You've got to get over that in order to survive in the South. ... Otherwise you just wallow in self-pity and hatred and you don't move forward."
Threatt had been inspired, in part, to be a lawyer by Arthur Shores, a pioneering civil rights attorney who fought to desegregate the University of Alabama. Shores' home was bombed twice in 1963, two weeks apart.
Shores' daughter, Helen, grew up resisting segregation, once drinking from a "white" fountain - a defiant act that resulted in a whipping when she got home. At 12, she aimed a Colt .45 at some white men driving by her family's house, spewing racial obscenities. Her father, she says, hit her arm, the bullet discharged into the air and he quickly grabbed the gun.
Shores Lee also left Birmingham, making the same pledge not to return. She too ended up changing her mind and eventually became a judge in the city.
In her early years on the bench, she recalls, a few lawyers pointedly refused to stand as is custom when a judge enters a courtroom. And, she says, she's occasionally seen lawyers who are disrespectful of their minority clients.
"Racism is still very much alive and well in the South," Shores Lee says. "The actions of men here can be legislated but not their minds and their hearts in terms of how they think and feel about blacks and Hispanics."
James Rotch, a white lawyer, launched the Birmingham Pledge in 1998 to eliminate racism and prejudice.
The "pledge" has evolved into a foundation with conferences, educational material used around the U.S. and a special week of events held around the September anniversary of the bombing of the Sixteenth Street Baptist Church that killed the four girls.
In the last 15 years, Rotch says the two races have become more comfortable with one another. And for those 30 and younger, "they really don't understand why anyone would be prejudiced," he says. "They intermingle easily and they just don't see what the big deal is."
Still, there are limits to the socializing.
King's dream is "real during the day" in workplaces and restaurants, says Jim Reed, a white bookstore owner. "When people aren't thinking about it, it's coming true," he says. Once home, however, they aren't inclined to broaden their circles.
"People don't know how to jump that divide," though some would like to, he says. "I see it as taking a long time to get there. Generations have to change."
At the More Than Conquerors Faith Church, Pastor Steve Green preaches to a congregation that couldn't have existed in King's day.
There are graduates of once-segregated universities. A generation of kids comfortable with mixed-race relationships. And people who worked to get out the vote for Barack Obama, the nation's first black president.
But there is one constant: Green's congregation is about 90 percent black, a reminder of King's frequently-quoted declaration that 11 a.m. on Sunday is "the most segregated hour of Christian America."
King, the pastor says, would turn to the Bible to explain that 50 years isn't all that long to transform an entire society.
"Being a preacher, I think he would use as the basis the scriptural principle of seedtime and harvest. I think a lot of the seeds have been planted," he says. "They're getting nurtured a little at a time. But I don't think it's harvest time yet."