The author had always thought it was State Rights… The Regents essays allow both answers… What’s the real deal?
Early secessionist Southern officials had plenty to say other southern states to entourage them to secede. Southern officials also had plenty to say after the war, and it was a totally different set of ideas.
Before the war, the important problem was racial equality, which would be terrible for the white elite, and racial purity, because blacks who were equal to white might actually marry the flower of white womanhood. (and they were right, miscegenation is barely even a word in America.)
After the war, it was state rights, not slavery, oh no.