LOL, that's just what I need for Christmas. A book by a plagarist on a man that worked to destroy the Constitution. Maybe for April Fools perhaps but even then it wouldn't warrant much more than being a doorstop.
I don't consider her a great historian. She is clearly a very partisan writer, and she has been caught plagarizing.
The Declaration of Independence, the U.S. Constitution and the Bill of Rights were a compass guiding Lincoln's Presidency. If Lincoln sanctioned cessation as a result of Southerner's disgust of the abolitionist movement, those documents would've been meaningless and forgotten pieces of paper today. What's fascinating about Lincoln is that he served the United States as though those documents were his personal identity. I disagree with you, IMO he saved the Constitution.
The deal seems to have been that the North (and Lincoln himself) underestimated the South's willingness to go through with secession because it had been threatening secession for a long time. And OTOH the South exaggerated the Lincoln position on abolition. Most of the Confederacy seceded before Lincoln's inauguration. Lincoln was not an Abolitionist, and was able to keep some border states within the Union throughout the war.
It is of course obvious now that secession did far more harm than whatever good it aspired to. And it is obvious that the war to restore the Union was drastically more expensive in every way than the Unionists ever imagined in 1861, as well.
Goodwin's book is fascinating because it treats the political issues of the Lincoln Administration, which of course had to have a great impact on the military proceedings.