I recently learned about the race riot in Cicero in the 1950s (?) when a black family tried to move into town... they were driven out by mobs of white people. You can see the outcome today in the sharp right angle delineating largely Hispanic neighborhoods of Cicero from African-American neighborhoods. The town still has almost no black residents.
When I was in Chicago, about 1970, a black family moved in on the west side of Cicero Blvd/Ave/St (the dividing line between Chicago and Cicero) in the afternoon, a mob formed, and the block captain moved them out that evening, with his boys moving out all their furniture. And that was the end of that. Nobody seemed to wonder why law enforcement seemed absent.