I would have said,"Well, the declaration says that the legtimacy of government comes from the consent of the governed and the vast majority of the south no longer consents to this union. So they have the right to "institute new government" that suits them better. If they think they can do it let them have a go. I recognize the acts of secession and wish you success. We will stand ready to aid in any way we can and look forward to the future. Sincerely, Ole Abe"
This is an interesting take on it all. The only problem is, as I see it, Lincoln thought it was his duty to preserve the Union. It fact, I think he had a vision that went beyond the Union as it existed prior to the attack on Fort Sumpter. For example, Lincoln thought a situation with California sitting three thousand miles away could not long continue without a better form of communication and exchange (i.e. railroads) being constructed.
No part of his vision called for the eleven seceded states existing as a separate country. This is an historical fact. As an aside, I have always sympathized with the attitudes of southerners in those days, at least with some southerners and to some extent. The great people of that era did what they did with the clear understanding that they were in the right. They gave it their all. Some won and some lost. We spend untold amounts of time second guessing that.
I prefer the attitudes of such giants as R. E. Lee or Joe Johnston. Theirs seemed to be that after giving 110% and finding it wasn't enough, the best thing is to try and pick up the pieces. James Longstreet thought losing was an abomination, but the Northerners weren't his enemy. The fact is, U.S. Grant may have been Longstreet's closest friend. None of these people could see the sense to fighting the war for another 136 years.
I guess in our society, Southerners (at heart) are supposed to depise Lincoln and Northerners (at heart) are supposed to despise Jefferson Davis. (Actually, Lee has to be despised by Northerners as a substitute pariah because most people these days don't know who Davis was.) I can't work up that kind of vitriol. I think Lincoln did what her had to do as he saw his duty. I have always found Davis to be an incredibly rock-willed and strong character.
Those that thought the preservation of the nation wasn't worth either the death or the attack on "rights" didn't win the election in 1860 or 1864. If they had, if McClellan had beat Lincoln in 1864, those that disagreed with Lincoln's vision may have had their way.
I always think those of us who like or dislike some historical figure really have an argument with fellow citizens of today. For myself, if there can be some way to preserve what I consider to be the "American" culture, then I think the preservation of the union is a worth while goal. Under those circumstances, for roughly 100 years after his death, I would argue that Lincoln was proved right.
If our "culture" can't be preserved, then I guess the dissolution of the Union is in order.
I have never thought the problem was "Lincoln." I don't think he could behave any different than he did. I have always thought the problem was and is that every time some rights are surrendered in any "emergency," you never get them all back after the "emergency" is over. We have had at least 3 or 4 emergencies since 1860. It's the loss of rights that are never recovered that make the current assault on the continuation of our "culture."