What you say comes down to the last line of my post: Victors write the history books. It could be argued that if Lee had not fought the third day at Gettysburg, the South would have had time to finish implementing the changes they were working on. 300,000 Black soldiers, trained and fighting for the promise of land and equality would have changed things. Once the war began, whether Slavery was the prime mover or not, Slavery was finished. With the historical result, we moved considerably toward Federalism.
The sort of Federalism that Lincoln gave us is the disease from which we are currently dying. I am sensitive as to how it got into our National blood stream. It certainly does not resemble the Federalism which our Founders had bequeathed us.
Lincoln, Roosevelt, Wilson, Roosevelt, Johnson, Carter, Clinton and Obama, all followed pretty much the same philosophy but to an ever expanding extent.