Sondheim was president of the Baltimore school board a half-century ago when in its Brown vs. Board of Education decision the U.S. Supreme Court found the racial segregation practiced within the public schools of 21 states to be unconstitutional. He moved quickly to comply and went about the thorny task of readying city schools for both black and white children by fall.
Indeed, five decades after the school desegregation decision, Americans appear to coexist in much the way Alexis de Tocqueville witnessed in 1835: "Almost insurmountable barriers had been raised between them by education and law, as well as by their origin and outward characteristics; but fortune has brought them together on the same soil, where, although they are mixed, they do not amalgamate, and each race fulfills its destiny apart."
Social scientists say nowhere is de Tocqueville's observation more true than at the residential level, where the country remains physically divided by race and class, the level where people become neighbors, kids make friends and school defines community.
The average white person in a metropolitan area, which includes city and suburban dwellers, lives in a neighborhood that is about 80 percent white (down from 88 percent in 1980) and 7 percent black, according to a 2002 analysis of Census Bureau data by the Lewis Mumford Center at the State University of New York at Albany.
By comparison, the average black person lives in a neighborhood that is 33 percent white (up from 30 percent in 1980) and 51 percent black. In general, the analysis found that blacks, Hispanics and Asians lived in more integrated neighborhoods than did whites.
Where we live matters 50 years after Brown, urban experts say, because racially segregated neighborhoods produce racially segregated neighborhood schools. And given the continued economic inequality between whites and minorities - a disparity Brown was never meant to remedy directly - such schools are also economically segregated with disproportionately high numbers of students from low-income families.
"It's all tied together," says Columbia University law professor Jack Greenberg, 77, who argued several desegregation cases that were combined in Brown vs. Board. "You're going to have to have better education in order to have better income. You're going to have to have integration to have better education. All this talk about equalizing schools is a lot of garbage. The only equality is integration."
The residential separateness occurs even though, when it comes to where we lay our heads, majorities of blacks, whites and Hispanics say they would rather live in a racially mixed neighborhood than surround themselves with only members of their own group, according to a Gallup poll conducted last year, one of many that suggest American platitudes and realities don't square up.
Why haven't we moved closer together, as those such as Sondheim hoped?
Sociologists point to ingrained attitudes about where certain races should live; economics; and discriminatory practices in the housing industry and public policies that perpetuate residential segregation.
Perspectives vary as to the primary cause, but the consensus seems to be that integration is about people, not laws, and the will to integrate is not fervent.
Indeed, many people are hesitant to call the separateness "segregation," pointing out that it is not sanctioned by law and claiming it largely reflects the personal preferences of those - of all races - with means and mobility. But the evidence suggests that prejudice plays a strong role: Blacks are more willing to live among whites than whites among blacks.
When middle-class black families move to the suburbs, white families often leave. Randallstown, for example, was 70 percent white in 1990; it is now 72 percent black.
The poorest families simply get left behind, creating concentrations of poverty that government housing programs have done little to alleviate. Today, two of every three African-Americans in the six-county Baltimore metropolitan area live in the city, according to an analysis of census data by Thomas Hylton, president of Pennsylvania-based Save Our Land, Save Our Towns Inc., which advocates for communities that are inclusive of all ages, races and incomes.
In the 1950s when white flight was fueled by such attitudes, Sidney Hollander Jr. stayed put in Northwest Baltimore's Windsor Hills neighborhood and fought against unfair housing practices like the "blockbusting" tactics used by real estate brokers to scare whites into selling their homes as blacks arrived.
Now his son, David, lives in the predominantly black neighborhood with his Chinese-American wife, Teri, and their 8-year-old daughter, Clara. Like his father, David believes in integration but says that Baltimore will remain racially segregated until it rebounds from what fueled white and, later, black middle-class flight: crime, poor performing schools and deteriorating infrastructure.
"If you deal with schools, economic development and what makes the city attractive, the integration will flow," says Hollander, 62, acting registrar at the University of Maryland, Baltimore County.