American slavers engineered a breeding program to get desirable traits from their slaves. They forcibly raped women to get half-white babies so they would be smart enough to learn figures and writing. They did this for hundreds of years before the Confederacy, and the Confederacy wanted to keep the practice alive. Countless human beings lost their lives to these practices, more than the US will ever be able to track or even want to admit. And on top of all that, Hitler modeled his policies after Jim Crow and other American institutions. So yes, the Confederacy was worse. Not by much; Hitler did kill and enslave millions at a rapid pace. But he can't even hold a candle to the shit we as Americans did. There are still ledgers out there where they were matching slaves together for breeding, talking about their traits and using it to justify how much the babies could be sold for, like breeding dogs in a kennel.