What was the secession movement about?
Money.
The Southern states would be better off financially with low tariffs that enabled their foreign customers to buy more of their goods. They would also be better off paying lower prices for the manufactured goods they did not produce.
There were other reasons such as them not liking centralized power and never having liked New England and feeling as though they were being taken advantage of, but the real issue at the heart of it all was money. They’d keep more if they were independent.
The reverse was true for the Northern states.
Apparently you believe the Succession Movement was ONLY about Slavery, it was not.