Lincoln was a racist tyrant who trampled the long held understanding of the the individual states that the states could voluntarily leave the union just as they had joined it.
Lincoln imprisoned his opponents only for publicly opposing him, pursued a scorched earth policy against civilians in the South, intended to relocate the black population to other countries, approved the slaughter native americans.
He sacrificed over 600,000 lives in preventing succession. The second American war of succession was about tariffs not slavery. It was an unnecessary war. Slavery ended without war everywhere else in the hemisphere.
I am in the process of studying Jefferson Davis and I don't claim to be an expert, it is not a simple situation. As repugnant as it may seem slavery was still commonly accepted by many people at the time as it had been for 3000 years.
I believe it was Davis' intent to release his slaves upon his death if the Confederacy had won the war. The emancipation proclamation only freed slaves in the confederate states where it had no ability to do so but not in the non-suceeding states where it could have. In any event the 14th amendment eliminated the opportunity for Davis to free his slaves.
At this point I would likely place him on the best presidents list but I need to do more research.