The Caddo are a nation, or group of tribes, of Native Americans who, in the 16th century, inhabited much of what is now East Texas, Western Louisiana and portions of southern Arkansas and Oklahoma. The Caddo historically consisted of three confederacies of at least twenty five different tribes and spoke a variety of dialects of the Caddoan languages. Today the Caddo are a cohesive tribe with their capital at Binger, Oklahoma, and the Caddoan dialects have converged into a single language.

The oral traditions of the Caddo suggest that they developed their culture in Arkansas and spread out to the south and west from there. At one time both the Wichita and Pawnee were part of the same nation as the Caddo, a fact attested to in that the Whichita and Pawnee spoke Caddoan languages. Between 500 and 800 AD the Caddo emerged as distinct and separate nation.

The Caddo tribes were divided into three confederacies, which were linked by a common language; the Hasinai, Kadohadacho, and the Natchitoches. The Haisinai and Kadohadacho live in what is now East Texas and the Natchitoches in what is now Northwestern Louisiana. The Haisinai lived in the land from the Nacogdoches, Texas, which was originally a Caddo settlement, area to the Neches River. The Kadohadacho settled the land from the Caddo Lake area to the Red River. The Nachitoches settled around Natchitoches, Louisiana, which was originally a Caddo settlement, and in the Cane River Valley.

The Caddo first encountered Europeans in 1542 when the Hernando de Soto Expedition came through their lands. With the arrival of missionaries from Spain and France a small pox epidemic broke out that decimated the population. The Caddo invited the European missionaries to return and upon their return a worse epidemic reduced the population to only 1,000.

In 1859, the state of Texas removed the remaining Caddo from its territory to a reservation in Oklahoma and in 1874 the Caddo officially united as a distinct tribe.

The Caddo lived in the Piney Woods eco-region of the United States up to the foothills of the Ozark Mountains. The Piney Woods is a dense forest of deciduous and conifer flora covering rolling hills, steep river valleys, and intermittent wetlands called Bayous. Several Caddo villages were resettled, including the community of Elysian Fields, Texas, and Nacogdoches and Nachitoches both of which have kept their original names. The Caddo were progressively moved further west until they reached what is now western Oklahoma. The geography of the drier plains was quite a contrast to the lush hilly forest that were formerly their homeland.