It's not exactly like the native Americans were peaceful and weren't trying to commit genocide against the other tribes now is it?
Mari Sandoz, the greatest author to come out of Nebraska, was known to be a remarkable scholar of the Native Americans.
Mari Sandoz was sympathetic to their plight.
But at the same time, Mari Sandoz pointed out that Native Americans were notoriously cruel, sadistic, homocidal, genocidal, towards both their own, and other Native Americans. It's not a pretty story.