Answer:
His leadership during the civil war.
Explanation:
During the civil war, Jefferson Davis served as a military leader for the confederate state. This means that he was fighting for the side that supported slavery.
That's being said, when we looked at his accomplishment objectively, many Generals of the Union at that time regarded Davis as the toughest military leader they'd have to fought.
Regardless of their inferior number and technology, Jefferson Davis always managed to implement smart strategies that made his soldiers came out on top.
