I don’t think it was possible for it to be resolved peacefully here.
It was a clash of societies and civilizations.
The pre war south’s entire societal structure was built on slavery. If the “peculiar institution” ended, it would fall apart. And they knew that. It went far beyond just the “act” of enslavement. The Ancien South’s entire society was built on top of it.
There was no other way it was going to end but with violence. Too many principled (morally warped principles, but principles nonetheless) men were involved.