The Siouan Indians (1897), published by the Bureau of Ethnology of the Smithsonian Institution

"Out of some sixty aboriginal stocks or families found in North America above the Tropic of Cancer, about five-sixths were confined to the tenth of the territory bordering Pacific ocean; the remaining nine-tenths of the land was occupied by a few strong stocks, comprising the Algonquian, Athabascan, Iroquoian, Shoshonean, Siouan, and others of more limited extent..."