The worst thing in world history I cannot say. But in recent history (last century) I would have to say that the Holocaust probably was the worst. I agree that all genocide is horrible, and yes, I think that pushing the Native Americans off their lands was horrible, and slavery was horrible, but the Holocaust is different.
Why?
I would say because there were so many people who were involved and KNEW what was going on. And it was pure torture, not even to mention the starvation. They did medical experiments on people in concentration camps. They performed surgeries, dental procedures, etc. without anesthetic. And they knew what they were doing.
