 The Caddo people speak a Caddoan language and is a confederation of several tribes who traditionally inhabited much of what is now East Texas, northern Louisiana and portions of southern Arkansas and Oklahoma.The tribe was once part of the Caddoan Mississippian culture and thought to be an extension of woodland period peoples who started inhabiting the area around 200 BCE.In an 1835 Treaty  made at the agency-house in the Caddo nation and State of Louisiana, the Caddo Nation sold their tribal lands to the US.