I can also see the capital being moved inland, away from Washington DC. The USA becomes a liberal state like Western Europe and Canada, and The CSA becomes a lot like Apartheid South Africa. I hope this helps!
Good map, and I think U.S. would be better without Dixie (at least Deep South), and I would not rule out emerging of such U.S. as superpower (holding or not holding Dixie doesn't play a role there). I also think it would be possible that U.S. and Canada became one state.
This is improbable map of strongest and biggest Confederacy: