Why are rural black parts of the South extremely rural?

[ProgressiveModerate]

I’ve noticed this tends to be a theme in the South where rural black areas tend to be even more sparse than rural white areas around them. Is this just due to depopulation or is there more going on here? It’s quite interesting because in state legislative maps for these states some of the largest districts are Dem and in SC and MS a Dem may be able to  actually win more “land” while loosing statewide.