The War of Northern Aggression.
Lincoln suspended habeus corpus.
He shit down newspapers for political position in violation of the First Amendment.
He began us on the course of an imperial federal government.
He pursued a war that killed over half a million American men.
Slavery would have died out - as it had in other countries - over time.
Africans were hardly the first peoples to be enslaved.
Had he not been killed would he have been remembered so fondly?
The "elite" would have loved him, but likely not so much the common man.
Then again, had he stayed in power, one of his pet projects that he worked on quite a lot, was getting the blacks to leave the country.
As the entire country, both North and South, were unreformed racists, he would have persisted in this plan, likely succeeded to some extent or other, and the general white population would have applauded him for it.
But this is speculation.