Well, I'll put it this way, yes, the South has a long history of racism. However, it's worth noting that most of the worst race riots of the Civil Rights Movements were in the Upper Midwest and North.
Racism has a tendency to be more overt in the South because southerners are more blunt about certain things, but people in other areas can be just as racist but in more subtle ways until physical violence happens.
Also, keep in mind that the most violent reactions to racially tense incidents in recent history have been in the Midwest as well, like in Ferguson, Minneapolis, and Kenosha.
I would argue race relations have come a long way in the South as compared with areas like the Midwest. Generally speaking, the areas with the largest black populations tend to have the least racial tension -- and the states with the highest black populations are usually in the South.
Areas that don't have a long history of significant black populations usually have more incidents and riots as their diversity increases. There's always an "adjustment" period involved.