According to the Miami Indians the Hopewell Mound Builders Were Sioux.
Migration Legends and Origins of Missouris's Siouan-Speaking Tribes, Bruce McMillan, Missouri Archaeologists, December, 2014
Ohio River Valley
The Ohio River valley was postulated as the place of origin for the Dhegihan-speaking tribes as early as the middle nineteenth century (Featherstonhaugh1844:70–71). Dorsey (1886:215) later claimed that the Dhegiha Sioux—the Osage, Kansa, Omaha, Ponca, and Quapaw—once lived together as a single nation in the Ohio River valley where they were known to the Illinois tribes as the “Arkansa” or “Alkansa.” The Jesuit missionary Father Gravier in 1700 elaborated by saying that both the Illinois and Miami Indians referred to the Ohio River as “the river of the Akansea,” because the “Akansea” formerly dwelt there (Shea 1861:120–121). In a sketch map prepared by Gabriel Marest, S.J., and sent to M. [Pierre le Moyne, Sieur] d’Iberville on July 10, 1700, the Ohio River is clearly labeled as the Acansea (Wood 2001:1, Plate 3). According toMcCafferty (2008:43), the map is in the handwriting of Jean Mermet, a fellowmissionary among the Miami-Illinois.
Gravier’s phonetic spelling for the Miami-Illinois word for Ohio River,
Acan-seasipi
