The culture area was an organising device of North American anthropology in the late nineteenth and early twentieth centuries, and the Plains is its best known example. It grouped nations by environment and economy: the Lakota and Dakota, the Cheyenne, Arapaho, Comanche, Blackfoot, Crow, Pawnee, Kiowa and others, speaking languages of at least five unrelated families and frequently at war with each other. The traits the label names are mostly recent.
The horse arrived in North America with the Spanish, spread north through trade and raiding during the seventeenth and eighteenth centuries, and made the mounted bison hunt possible; several of the nations most associated with the Plains had been farmers further east within living memory of the ethnographers who described them. So the grouping records a way of life that existed, in the form described, for about two centuries, and it presents it as timeless. It persists because museums organised their collections by it, because the Bureau of Indian Affairs and its equivalents administered by it, and because it supplied the imagery that stands for indigenous North America in the popular mind, to the exclusion of everyone else. The nations themselves have their own names and their own accounts of who they are, and those are what the atlas uses on the individual entries. This page exists so that a reader who meets the collective label can find out where it came from.