[majormajor]

History makes it pretty clear that southerners were, on the whole, much more openly and institutionally racist than northerners both before and after the Civil War.

The ones that seceded said it was about slavery. Many times. You don't believe them. Why? Why do you care enough to claim that you know their motives better than everyone else?

West Virginia split because they didn't want to go along with Virginia's secession. That's something that happened after the cause, not something that can tell you the cause, though! Maryland and Delaware were less dominated by the slave-holding interests. Its not that interesting.