Was it because they couldn't imagine a South without slavery?
You might ask instead if it was because they couldn't imagine a future where they were impoverished, powerless, and at the mercy of Northern financial and manufacturing interests because they had been stripped of their entire economic system. THAT is what an end to slavery meant to the South in 1860.
And indeed, that was absolutely the case right up until the 1960s in most areas of the South. Impoverished and powerless for a hundred years after the end of the war.
