Unfortunately the Federal Government was hardly blameless in the racial issues. The single greatest tragedy in the history of race in the US was when the administration of Andrew Johnson rejected Sherman's efforts at land reform in the South. This would have lead to a very segregated South, but former slaves would have had means of production so the segregation could not have been pernicious, as it was (and still is as de facto segregation based on massive economic inequality).

The federal government, effectively, has been a party to the worst of these problems, by advocating for the last 150 years, that black folks "getting a job" will solve the issue. It never has and it never will. Give a man a fish and he'll be back tomorrow, which is why Sherman was more interested in giving them metaphorical fishing boats.

I have now lived in areas where there is a lot more racial separatism than there is in the US. In the absence of massive economic inequality, that poses very little problems. The problems in the US have been racial separatism backed by massive inequality out of the starting gate, something bolstered more than hindered by federal policy (though the states have been bad guys here too). But because we can pick and choose which bad guys we want to condemn, we can imagine that the feds messed up everything or that they saved people from the evil states. In reality there is plenty of blame to go around.

I like the Scandinavian model: most taxes go to the local level and most social programs are run at the local level. Sweden and Denmark, for example, have no national single payer systems (rather municipalities set up single payer systems). However on the spectrum of American politics that makes Scandinavians both far-left and far-far right....