Osage, Omaha, Mandan, Kansa and Akansea, and Ponca, concur that they formerly dwelt in the Ohio Valley.
"The Popular Science Monthly,” “The Sioux and Iroquois Legends, Prehistoric Aborigines of Minnesota and Their Migrations.” N.H. Winchell, 1908
“The Osage and perhaps the Omaha, who belong to the Dakota stock, and who have a tradition which is confirmed by other traditions, that they once lived east of the Mississippi in that very region, [southern Ohio].
With this understanding it is, I repeat, a remarkable fact that, aside from the Muskogee earthworks of the gulf coast, which have distinctive characters, only the Dakotan and Iroquois stocks can be shown either by history or tradition to have been characteristic mound builders.
This legend is found amongst several of the Dakota tribes, and even amongst the later Algonquin who returned westward to the Mississippi Valley. The Osage, Omaha, Mandan, Kansa and Akansea, and Ponca. These tribes concur in saying that they formerly dwelt in the Ohio and Wabash valleys, and that they moved down the Ohio Valley, where they were separated into two divisions at the mouth of the Ohio River, some of them going down the Mississippi and some of them up the same river.
It is due to the research of the Late J. V. Brower that the Dakota tribes of Minnesota have proved to belong to the so-called mound-builder dynasty.
There is also a remarkable series of effigy mounds in central and southern Wisconsin, which extended across the Mississippi into Minnesota and Iowa. As to the prevalence of serpent worship, we have shown that there were serpent effigies in Ohio, Illinois, Minnesota, Wisconsin and Dakota, and that all these were situated along the line of migration, which according to tradition of the Dakotas, was followed by their ancestors on reaching their later seats on the Mississippi and Upper Missouri Rivers.” We may conclude from this that the Winnebago were not only effigy builders, but they were serpent worshipers, and that these various serpents were their work.”