Saying the civil war was about some principle of state’s rights is precisely what’s misleading and wrong.

The southern states who later seceded were the ones pushing the fugitive slave act, trying to impose their will on the northern states, a direct contradiction to the idea of “states’ rights.” And as you can see if you read the letters to secession yourself, they directly cite their inability to enforce slavery laws in northern states as the reason why they should be able to leave the union. No consistent high minded principle about state autonomy. All about maintaining slavery, however possible. And the threat of an anti slavery president was the last straw for them. Later when they wrote their own constitution, there was nothing about states’ rights to decide on slavery laws, the new confederacy deemed every state must allow slavery and wrote it into their constitution. Again, not “states rights.”