There were a lot of issues that led to the Civil War, with the primary two being slavery (obviously reprehensible) and state rights (one of our founding principles). I think it’s safe to pity Lincoln, insofar as he was forced to address an issue that the Founding Fathers punted since they couldn’t solve it. So, depending on which issue you focus on, you can frame Lincoln as a hero or a villain, and that’s not something I hope to be able to settle.
But I will say one thing: This very smart man saw how things would ultimately play out in this country:
“We may congratulate ourselves that this cruel war is nearing its end. It has cost a vast amount of treasure and blood. . . . It has indeed been a trying hour for the Republic; but I see in the near future a crisis approaching that unnerves me and causes me to tremble for the safety of my country. As a result of the war, corporations have been enthroned and an era of corruption in high places will follow, and the money power of the country will endeavor to prolong its reign by working upon the prejudices of the people until all wealth is aggregated in a few hands and the Republic is destroyed. I feel at this moment more anxiety for the safety of my country than ever before, even in the midst of war. God grant that my suspicions may prove groundless.”
The passage appears in a letter from Lincoln to (Col.) William F. Elkins, Nov. 21, 1864. (Source: “Abraham Lincoln, a New Portrait” (1931)).