The ancestry and prehistoric movements of the tribes constituting the Ɉɔiwe’re group are involved in considerable obscurity, though it is known from tradition as well as linguistic affinity that they sprung from the Winnebago.
Since the days of Marquette (1673) the Iowa have ranged over the country between the Mississippi and Missouri, up to the latitude of Oneota (formerly upper Iowa) River, and even across the Missouri about the mouth of the Platte. Chauvignerie located them in 1736 west of the Mississippi and (probably through error in identification of the waterway) south of the Missouri; and in 1761 Jefferys placed them between Missouri river and the headwaters of Des Moines river, above the Oto and below the Maha (Omaha). In 1805, according to Drake, they dwelt on Des Moines river, forty leagues above its mouth, and numbered 800. In 1811 Pike found them in two villages on Des Moines and Iowa rivers. In 1815 they were decimated by smallpox, and also lost heavily through war against the tribes of the Dakota confederacy. In 1829 Porter placed them on the Little Platte, some 15 miles from the Missouri line, and about 1853 Schoolcraft located them on Nemaha river, their principal village being near the mouth of the Great Nemaha. In 1848 they suffered another epidemic of smallpox, by which 100 warriors, besides women and children, were carried off. As the country settled, the Iowa, like the other Indians of the stock, were collected on reservations which they still occupy in Kansas and Oklahoma. According to the last census their population was 273.
The Missouri were first seen by Tonty about 1670; they were located near the Mississippi on Marquette’s map (1673) under the name of Ouemessourit, probably a corruption of their name by the Illinois tribe, with the characteristic Algonquian prefix. The name Missouri was first used by Joutel in 1687. In 1723 Bourgmont located their principal village 30 leagues below Kaw river and 60 leagues below the chief settlement of the Kansa; according to Groghan, they were located on Mississippi river opposite the Illinois country in 1759. Although the early locations are somewhat indefinite, it seems certain that the tribe formerly dwelt on the Mississippi about the mouth of the Missouri, and that they gradually ascended the latter stream, remaining for a time between Grand and Chariton rivers and establishing a town on the left bank of the Missouri near the mouth of the Grand. There they were found by French traders, who built a fort on an island quite near their village about the beginning of the eighteenth century. Soon afterward they were conquered and dispersed by a combination of Sac, Fox, and other Indians; they also suffered from smallpox. On the division, five or six lodges joined the Osage, two or three took refuge with the Kansa, and most of the remainder amalgamated with the Oto. In 1805 Lewis and Clark found a part of the tribe, numbering about 300, south of Platte river. The only known survivors in 1829 were with the Oto, when they numbered no more than 80. In 1842 their village stood on the southern bank of Platte river near the Oto settlement, and they followed the latter tribe to Indian Territory in 1882.
According to Winnebago tradition, the Ɉɔiwe’re tribes separated from that “People of the parent speech” long ago, the Iowa being the first and the Oto the last to leave. In 1673 the Oto were located by Marquette west of Missouri river, between the fortieth and forty-first parallels; in 1680 they were 130 leagues from the Illinois, almost opposite the mouth of the Miskoncing (Wisconsin), and in 1687 they were on Osage river. According to La Hontan they were, in 1690, on Otontas (Osage) river; and in 1698 Hennepin placed them ten days’ journey from Fort Crève Coeur. Iberville, in 1700, located the Iowa and Oto with the Omaha, between Wisconsin and Missouri rivers, about 100 leagues from the Illinois tribe; and Charlevoix, in 1721, fixed the Oto habitat as below that of the Iowa and above that of the Kansa on the western side of the Missouri. Dupratz mentions the Oto as a small nation on Missouri river in 1758, and Jefferys (1761) described them as occupying the southern bank of the Panis (Platte) between its mouth and the Pawnee territory; according to Porter, they occupied the same position in 1829. The Oto claimed the land bordering the Platte from their village to the mouth of the river, and also that on both sides of the Missouri as far as the Big Nemaha. In 1833 Catlin found the Oto and Missouri together in the Pawnee country; about 1841 they were gathered in four villages on the southern side of the Platte, from 5 to 18 miles above its mouth. In 1880 a part of the tribe removed to the Sac and Fox reservation in Indian Territory, where they still remain; in 1882 the rest of the tribe, with the remnant of the Missouri, emigrated to the Pouka, Pawnee, and Oto reservation in the present Oklahoma, where, in 1890 they were found to number 400.