There is a reason for it, but you will never read it in a history book or be taught it by a public school teacher, or even hear a talk show host address it.
Blacks and whites in the south have been working, living, and dying together for generations, inspite of every attempt to eliminate the racism of only a few.
I was once hoping that the sense of civility might spread north and to the bigger cities, but everytime it looks like it might, some rabble rousing community organizer comes along.
Even the young today, even in the south are lacking in the old southern social skills that make it possible to live together in peace. I think it’s because their parents did not pass it along, and perhaps the primary reason is that the social compact of the entire country as founded is being wiped away, destroyed, or hidden..and certainly not taught in schools.
This social compact is a requirement for the continuation of the US as a monument to democracy, the shining light and all that...but without it we will devolve into a seething pile of excrement.
Heck, even the really nice gated communities are ethnically mixed.