How Queens became segregated: Welcome to the southside

School District 28 in Queens, N.Y., has a Northside and a Southside. To put it simply, the Southside is Black and the farther north you go, the fewer Black people you see. But it wasn't always like this. Once the home to two revolutionary experiments in integrated housing, the Southside of the district served as a beacon of interracial cooperation. So what happened between then and now?