Okay, so I've been thinking about this and now I'm kinda stumped on a few bits.
I've got a rough idea of what exactly happens to form a confederate states that's primarily run by african americans, but apart from the basics timeline: Confederates win pyrrhic victory then black slaves revolt while white masters are weak, I'm unsure about other things.
For instance, would the Union support it? (I doubt so but the US has a habit of supporting regime changes all the way from Hawaii and Mexican owned California)
Would there be white flight, and to what extent? Would it be like Zimbabwe? Would states secede from the confederacy to the union?