After, it seems, binge watching Ken Burns' old Civil War documentary, Donald Trump offered that the matter could have been settled by the right deal maker. The South, he added, "overplayed its hand."
Some political types are treating this as a gaffe likely to offend Southerners, but I think it's an interesting question. Suppose the Republicans had nominated, not the extremely principled Lincoln, but a more transactional politician like Simon Cameron. Was there a deal to be made between North and South? A new Missouri compromise?
I tend to think not, although I would be curious what others have to say. The Republicans ran on a pledge to exclude slavery from all the territories and recognize the free state government of Kansas. It would have been difficult for any Republican president to go back on those promises, and I doubt Southern leaders would have accepted any deal that did not allow them some new territory to claim in the west.
But I suppose that depends on how you see Southern goals. If their goal was to preserve slavery and the society that depended on it, then they absolutely "overplayed their hand." The war ended slavery much more quickly than any other conceivable means, and did more damage to the plantation economy. So if you think the goal was only to preserve slavery as long as possible, the South played their hand about as badly as possible. Perhaps a different Southern leadership would have let Fort Sumter alone and tried to negotiate the best deal they could short of war. Perhaps, say, Texas could have been extended to take in the upper Rio Grande valley, as a sop to secessionist firebrands, accepting anti-slavery control of the rest of the west.
I have always thought, though, that the key to understanding Southern behavior in 1861 is not slavery but honor.
One way to imagine Southern behavior is to see the Southern elite proclaiming, "They won't take our slaves without a fight." This made slavery an issue, not just of economics, but of honor. When the election of Lincoln seemed to portend the eventual end of slavery, they said, "We might as well fight now; things will never get better for us in a Republican-dominated Union." So they fought. Having fought hard for four years and won their share of battles, they took the surrender of Lee (the perfect gentleman) as a sign that honor had now been served. So they made peace with the Federal government, accepted the legal freedom of their slaves, and set about fighting within the Union to preserve their key political goals, white supremacy and an expansive view of private property rights. In those causes the history and rhetoric of the Lost Cause, along with the camaraderie and bloody-mindedness built up in four years of war, turned out to be great assets.
I tend to think that the violent spasm of war was a necessary background to that transition. As Virginia Governor Wise put it, "God knew that we could be torn away from our black idol of slavery only by the destroying angel of war."