Who Belongs Where?

You show the Sioux (Lakota) in the Great Plains. But apparently they originated in the forests of Minnesota and Wisconsin. They were forced from their homes by eastern tribes onto the plains. There they displaced the Crow, who became their enemies and served as scouts for the Army.

So who, exactly, belongs where? Everyone on Earth came from somewhere else. If someone located a group of Neanderthals surviving in a forest somewhere, by your logic they could claim the whole Earth.