[Physicist]

Well, I think a more important factor was that the key issue, slavery, had been eliminated. You can argue about whether either the Union or the Confederate government went to war specifically over slavery, but for many of the people, slavery was the reason. Once that issue had been irreversibly decided, much of the passion drained out of the conflict. The northerners got their way, and so had no further motivation to oppress the southerners (many of whom were freed slaves anyway). The southerners lost their labor force, so the civilization of the Old South could never be put back again, Union or no.

[Destro]

I guess it boils down to the fact that many White Southerners did not feel loyalty to or like the Slave owning landed class much and were not about to fight a guerilla war to restore back a rich man's ex-slave or plantation. They were willing to fight for States Rights and after the war and Reconstruction they got just that so the animosity to the Union died down and the thirst of the next Southern generation to revenge the loss went with it. It does seem to make sense that "terrorist" groups in the South were formed during Reconstruction and were repudiated and died down as Reconstruction was lifted. That sound about right?