Declaring marshal law - he was the first tyrant President and he didn't care about the slaves...he only cared about preserving the union, like a typical politician he used freeing slaves as a way to rally the north together to fight the south's secession movement. So greatest accomplishment was being the first president to declare marshal law and remove habeas corpus ( making him the first president to overstep his authority and put America under tyranny) - your professor may enjoy watching you take this position as not many people knew this happened
