At the time of European contact with Native communities, the Caddos (who call themselves the Hasinai) were accomplished traders living in the southern plains. Their communities occupied parts of present-day Texas, Arkansas, Louisiana, and Oklahoma. It was early Spanish explorers who named a part of this territory "Texas," borrowing the Caddo word for "friend." Today there are approximately thirty-five hundred Caddos, most of whom live in Oklahoma. Their original language, which is related to the Plains languages-Pawnee, Arikara, Kitsai, and Wichita-is rapidly dying and is spoken only by a...