It's not just those areas. I had some months of "door-knocking" experience in Chicagoland, early noughties. The neighbourhoods tended to be racially segregated:

It's not just those areas. I had some months of "door-knocking" experience in Chicagoland, early noughties. The neighbourhoods tended to be racially segregated: Latino, white, or black. As a white person, we were often warned to avoid certain latino or black neighbourhoods by police and civilians, yet they were almost always more friendly and welcoming than white neighbourhoods, and never ended up being dangerous. In the white neighbourhoods there was a tendency to be greeted with suspicion, aggression, loud guard dogs, threats, and occasionally with guns. I imagine that the difference would be more pronounced if I was black and walking around in those same neighbourhoods.