Okay, once again, this is another Confederacy TL BUT, I have a different suggestion than most.
What if, because of the institutions built before hand during the ACW, the Confederacy becomes the very first Fascist state, decades before Fascist Italy? I say Fascist because it had many of the requirements of Fascism, including a siege mentality, totalitarian elements, and a group to oppress. Under the right circumstances, one could even argue it's heading towards Nazi Germany light, the last bit only referring to the lack of direct killing of minorities.
Economically, it would be likely to adopt corporatist, as the government and planters are already quite intertwined. Add in its militarization wants, and totalitarian elements, corporatist economics could result.
So again, this isn't just a military dictatorship, this is an outright Fascist state, with elements of Fascist Italy and/or Nazi Germany decades before either existed.