You got the social programming around the wrong way.
Slavery was good.
Slavery was legal.
Everyone loved slavery.
Slavery kept he economy strong.
That was the State of The Union.
It's Lincoln who changed the status quo and rebelled against every normal human instinct that civilization insisted that slavery was necessary and morally justifiable.
The Confederates weren't rebelling against dick.
They just wanted to keep everything the same as it had always been.