The South was a society and economy totally dependent upon human tyranny and slavery to survive.
That's simply untrue. The vast maj of southern whites didn't own slaves, but rather were subsistence farmers or small merchants. The wealth in the south was tied to land and slaves, and held by an elite.
While the poor whites fought and made up the manpower of the armies, it wasn't to support the white master on the hill. Ideologically, they opposed the North's power to outvote them in Washington to favor northern manufacturing, and they truly believed in states rights. In 1861, there was nothing radical in the notion that states could leave the union. The constitution didn't prohibit it, and there was (-: that amendment about powers not enumerated were reserved to the states.
The worst you can say about most white southerners was they didn't import all these slaves, and they didn't want millions of them (I think the figure is two slaves for three poor whites though it's been awhile since I looked, and I'm not inclined) running free in the countryside competing with them for land and food.
And that's how we got the Klan. Later, it turned into a tool of the elite. Before WWII they were dependent upon cheap, terrorized labor. After WWII it simply came down to a rich man hides by giving poor men poor enemies.