@coldjoint,
In this case, the use of Hitler is relevant, both represent a horrible time in history. If you have a statue or image of a person in history, that means the people of the city, town, state, whatever, revere that period or person who represents that event or period in time. I don't revere the people who fought on the side of the confederates who were fighting to preserve slavery even if they are my own ancestors.
If you want an image up to represent the time in history, there have been artist who have drawn images of slavery and what the slaves endured. Or you could have images of the civil war and how it devastated the south.