Um as far as the civil war goes. Secession began once Lincoln was elected out of a belief that he was Anti-Slavery (see "Northern Interests") and that the "North" as a populace had become more unified in Abolition. Seven states we're out by the end of Lincoln's incumbency.
Also states rights is thrown around a lot. For the South it was the idea that a state could act and govern with some level of independence (i.e. IGNORE certain federal policies that would abolish slavery). And the North would carry on progressively and adapt, relying on industry in comparison to the South's agricultural bias. And since 1793 the use of slave labor for cotton production specifically had exploded, becoming the cornerstone of Southern agriculture. Without free labor, profits would dive. Sure they could change, but these are OG Conservatives we're talking about here. Picture telling GM's brass when profits were at an all time high that they had to compensate or terminate any and all automated equipment that helped create their automobiles.

"Why would you pay something that has no emotions, and can't think. It's not like they're real people."