I don't see anyone here disputing that. It was more than just slavery - it was the leaders of the south thumbing their noses at the rest of the country and proclaiming, "We'll have our slavery if we have to destroy the whole country to keep it!"
Nice guys.
You keep saying that the South was trying to destroy the Union. Why can’t you just admit that they weren’t trying to destroy the Union so much as trying to leave it? Is it really so hard to admit that the Union could have continued on without the South?