But Lincoln certainly did attempt to negotiate by offering "a fort for a state" meaning Sumter for Virginia.
But Virginians turned down Lincoln's offer.
As for Confederate "emissaries", the Constitution requires that Congress has authority over such matters.
But no "emissary" ever asked Congress for anything.
DiogenesLamp: "The evidence indicates that Lincoln never had any intention of respecting the principle that States can become independent."
No, the evidence from Lincoln himself demonstrates he had every intention of peacefully respecting Southern arrangements, so long as minimum constitutional functions were performed.
DiogenesLamp: "And really that is the crux of the matter isn't it?
Whether states have a right, as proclaimed in the Declaration of Independence, to become Independent, or whether our principles of governance requires the forcible subjugation of people who are no longer happy with the existing government and wish to leave it."
No, as we've shown over and over again, no Founder believed in an unlimited "right" to unilateral declarations of secession "at pleasre" or for "light and transient causes".
All were at pains to insist that declaration of disunion was a last resort, when all else failed, not a first resort whenever somebody wakes up with a headache.
DiogenesLamp: "All the rest is just spinning."
All the rest of you argument is just nonsense.
We've already covered that. Lincoln had no legal power to do such a thing. If states have a right to leave, Lincoln could not tell them "no." If States have no right to leave, Lincoln cannot tell them "Yes."
It is an abuse of power on the very face of it.
It doesn't matter what "The Deal" was, Lincoln did not have the constitutional authority to make such a Deal.
Either the matter of states leaving was an affair for the entire government, and especially the Congress, or it was entirely a matter of the States being free to do as they wished.
From a constitutional standpoint, I don't see where Lincoln has any power to "Make a Deal" over the issue.