Confederates were American, in fact they were extra American. The most American of the Americans. The most pure distillation of the Classical Liberal Slavery ideology that America represents.

They only fought Nazis because Nazis declared war on them first and America happened to have the farthest left leaning president in its history at the time to push the nation the right way. There were significant political movements to ally with Nazis and adopt fascism ourselves, including business plot coups and major industrialist funding. Immediately after the war we absorbed Nazi command structures and reimplemented them, reinstalling fascists back into power