Indigenous peoples of the Southeastern Woodlands, Southeastern cultures, or Southeast Indians are an ethnographic classification for Native Americans who have traditionally inhabited the area now part of the Southeastern United States and the northeastern border of Mexico, that share common cultural traits. This classification is a part of the Eastern Woodlands. The concept of a southeastern cultural region was developed by anthropologists, beginning with Otis Mason and Franz Boas in 1887. The boundaries of the region are defined more by shared cultural traits than by geographic distinctions.[1] Because the cultures gradually instead of abruptly shift into Plains, Prairie, or Northeastern Woodlands cultures, scholars do not always agree on the exact limits of the Southeastern Woodland culture region. Shawnee, Powhatan, Waco, Tawakoni, Tonkawa, Karankawa, Quapaw, and Mosopelea are usually seen as marginally southeastern and their traditional lands represent the borders of the cultural region.[2]
The area was linguistically diverse, major language groups were Caddoan and Muskogean, besides a number of language isolates.