Personally, I think balkanization or civil war are the most likely outcomes. The US has a lot of cruft from generations of oligarchy and the spared leadership from the Confederates. It would require a deep cleaning and reorganization to secure a better future for many states.

Anyhow, I believe that the American Dollar would probably die. If the US balkanizes, we might see a Californian Peso or Pacifican Bills to become a thing. Being anchored to a sinking currency would kill many states, so it would behoove them to separate on the fiscal basis alone.