So many topics you've brought up here. The US is one of those countries that erases their history. We ware taught a version of slavery that makes white people the heroes. Society was temporarily redirected because of the deaths of a few because it ignored the previous deaths and conditions of many. Fear not, it's gone right back to ignoring them.

Some of the communities you describe, not unlike white communities in Appalachia, are more violent due in part to their circumstances. They should be policed but changing the underlying conditions is the bigger need.