But today, the concern isn't the slow pace at which desegregation first occurred. It is the steady erosion of its gains.
A recent study by the Harvard Civil Rights Project found that since 1991 - when a Supreme Court decision letting Oklahoma City return to neighborhood schools from more racially balanced ones, prompted many lower courts to free districts from judicial oversight - many districts have to a large degree resegregated.
Some demographers take issue with the way the study defines segregation, but its results show that nationally, the percentage of black students attending majority white schools fell from a high of 44 percent in 1988 to 30 percent in 2001.
Desegregation "isn't a failure," says Gary Orfield, coauthor of the report and a leading expert on school integration. "Where it's happened, we've had really successful results. The main reason we're going back is that we've stopped trying."
His research shows the success of Brown as well as the failures. Between 1964 and 1970 alone, the percentage of blacks in majority white schools in the South went from 2 percent to 33 percent.
But the early 1970s also brought a pair of Supreme Court decisions that dealt severe blows to Brown's effectiveness. A 1973 ruling turned down an appeal aimed at equalizing school financing. And Milliken v. Bradley, the famous Detroit case from 1974, determined that city and suburban districts couldn't be required to merge to desegregate a metropolitan area.
The Milliken ruling was a particular blow to desegregation efforts that were just beginning in the North. It accelerated the already rapid white flight to the suburbs.
At Harlan, former assistant principal Richard Thompson recalls that "one year we came back and whoosh - all the white people had gone."
Today, Chicago's public schools are only 9 percent white. Cities like Detroit saw a similar white flight, and school systems in Illinois and Michigan remain among the most segregated in the country.