Memes

Honestly the worst thing Lincoln ever did was choosing Johnson as his VP. Even then, I learned recently that he asked a different (better) guy, Benjamin Butler, to be VP but he turned him down. Had he lived to do Reconstruction, we might have more to critique, certainly he'd have done better than Johnson (not a high bar), but since he died he's off the hook for figuring that one out.

You could also criticize him for not being committed enough to ending slavery from the start. But really, other than the mass hangings of the Dakotas (which could've been worse but was still not great), most criticism of him is just Lost Causers whining about "authoritarianism" by freeing the slaves and expanding the scope and power of the federal government as was necessary to free the slaves.

It is telling that while you can't think of something cartoonishly evil he did off of the top of your head- you definitely remember that he was assassinated.

Edit: Apparently this edit is required. Whether Lincoln held the mission of abolishing slavery personally or not, he was associated with it. And was shot in cold blood for it. Do something less than the worst thing you could do as president and the American project will answer your arrogance.