re: Remember when it was about states rights?

It was about states rights. Lincoln didn’t even make slavery an issue until after Antietam in September of 1862.

The South had a right to secede. There wasn’t anything in the Constitution at that time that prohibited it. In fact, James Madison believed:

Hamilton and Madison hoped secession would never happen, but they never denied that it was a right and a practical possibility. They envisioned the people taking arms against the federal government if it exceeded its delegated powers or invaded their rights, and they admitted that this would be justified. Secession, including the resort to arms, was the final remedy against tyranny. (This is the real point of the Second Amendment.)

Hamilton and Madison were correct.