Lately, I've been fascinated by the idea of the latest possible aversion of the American Civil War. The last option I can think of (and granted, an unlikely turn of events), is Robert Toombs being chosen as President of the Confederacy rather than Jefferson Davis. Toombs, IOTL the Confederate Secretary of State, was entirely opposed to attacking Fort Sumter:
"Mr. President, at this time it is suicide, murder, and will lose us every friend at the North. You will wantonly strike a hornet's nest which extends from mountain to ocean, and legions now quiet will swarm out and sting us to death. It is unnecessary; it puts us in the wrong; it is fatal."
So, with Toombs' passionate opposition to firing the first shot, would it have been possible for conflict to be put off long enough for the North and South to re-unify, on the condition of the Corwin Amendment being ratified, which would've permanently (from a constitutional perspective) entrenched slavery in the states in which it already existed? Lincoln voiced support for the Corwin Amendment, and could have used it as an out for his 'preservation of the union above all else' stance. Was there any chance of this happening, or were there too many hot-headed secessionists and chances of a borderland shootout by that point to make (semi-)peaceful reunification completely impossible? If so, what about a President Stephen Douglas and Toombs agreeing on the more pro-slavery Crittenden Compromise?