A friend of mine attended Decatur High School some 25 years ago. Back then, he told me, the school's student body by reputation was 80% black. (Although to a 120 lb white freshman from the sticks, it looked closer to 95% black.)
Not anymore. Decatur High School's student body is now only 47% black . . . and 46% white! It has a respectable 8/10 rating from GreatSchools.net.
How did this happen? Normally among families with school-aged children, blacks are displaced by Hispanics, not whites. And while neighborhoods can gentrify, they are usually gentrified by homosexual or otherwise childless whites. People contemplating families usually move to the 'burbs, of which the Atlanta area has an abudance. Once schools become "black", no white family wants to send their kids there, even if whites are a majority in the community.
Consider, for instance, the Buckhead area (of A Man in Full fame) in north Atlanta. Overwhelmingly rich and (~85%) white, Buckhead's public high school is nonetheless only 13% white and scores a dismal 3/10 from GreatSchools.net. Clearly, even with per pupil expenditures in excess of $12k, white families have written off North Atlanta High.
Decatur, meanwhile, is presently 65% white. I have no knowledge about its demographics over time, but as the longtime home of Agnes Scott College and Columbia Seminary, it certainly has its share of white pointy-heads. But how did white students achieve parity at Decatur High?