Balkanized USA, but a little different.
The CSA gains independence after the Civil War, Deseret gets it's independence somehow, and takes over a few Mormon minority states. Texas gets independence from the CSA, takes over New Mexico and Arizona, establishes the Empire of Texas (I wrote Kingdom, since Empire of Texas might play too much into current stereotypes), they win territory from the CSA and some other nations.
The USA has a socialist revolution, which makes some go "VLUH I'm not gonna get involved in that" and declare independence. Nations form up...wars happen, and by whenever, we have a balkanized, cool looking USA.
I got the idea for the Texan Empire from the Amarr Empire in EVE Online...douchebags who think their entitled to rule everyone.
I might make this a Hears of Iron III mod.