Sioux, Or Dakotas, a tribe of American Indians, dwelling near the head waters of the Mississippi when first known by the whites. In 1640 the Algonquins informed the French of them as the Nadowessioux, whence they came to he called Sioux. In 1660, or soon after, the Chippewas and Hurons began a war with them, which continued into this century. In 1680 Duluth set up the French standard in their country at Izatys near the St. Peters. In the next year he rescued Hennepin from them. Nicolas Perrot, having entered their domain in 1685, took formal possession for France in 1689, erecting a breastwork near Lake Pepin. In 1689-'99 Le Sueur visited the Dakotas, and describes them as divided into seven eastern and nine western tribes. They joined the Foxes against the French, and in war with the Chippewas many were forced down the Mississippi, and, driving other Indians from the buffalo plains, took possession of them. Several bands wandered into the plains of the Missouri. Some remained at or near the St. Peter's. The English agents secured the services of the Sioux in the war of 1812; but most of the bands soon made peace.

The treaties then made were renewed in 1825 by the Tetons, Yanktons, and Yanktonais, Si-oune, Ogallalas, and Oncpapas. The nation, estimated in 1822 at 5,000 on the St. Peter's and 7,750 on the Missouri, comprised the Alde-wakantonwans, or Spirit Lake village; the Wahpetonwans, or village in the Leaves; the Sisitowans, or village of the Marsh, called also Isantis; the Yanktonwans, or End villages; and the Tetonwans, or Prairie village, which includes the Ogallala and Oncpapa bands. Their territory extended from the Mississippi to the Black hills, and from Devil's lake to the mouth of the Big Sioux. On Sept. 29, 1837, the Dakotas ceded to the United States, for $300,000 and some minor payments, all their lands east of the Mississippi. The American board began missions among the Wahpetonwans near Fort Snelling in 1835, and the Methodists in 1836. Schools were introduced, and elementary books printed in the language. In 1851 the nation ceded to the United States all their land east of a line from Otter Tail lake through Lake Traverse to the junction of the Big Sioux and the Missouri, retaining a reservation 20 by 140 m.; 35,000,000 acres were thus acquired for $3,000,000. The government's neglect to carry out the provisions of these treaties caused bitter feelings, and in 1854 Lieut. Grattan, in the attempt to arrest a Dakota, attacked a village and was cut off with his whole party.

A series of hostilities by some of the Sioux ensued; but Gen. Harney defeated them on Little Blue Water, Sept. 3, 1855, and a general council at Fort Pierce consented to a treaty of peace. But in July, 1857, the band of Inkpa-dutas massacred 47 whites near Spirit lake, Minnesota, and murders elsewhere followed. Five whites were killed at Acton, Minnesota, Aug. 17, 1862. Enraged by the failure of annuities and the frauds practised on them, the Sioux then made a general uprising and killed nearly 1,000 settlers. New Ulm, a town of 1,500 people, was abandoned and almost destroyed. Fort Ridgely was besieged, and was saved with difficulty. The Sioux of the Missouri and the plains also became hostile, and were reduced by Gen. Sibley of Minnesota and Gen. Sully of the United States army. After a severe struggle a number of captive white women and children were rescued, and many Indians captured and sent to Davenport. Of more than 1,000 Indians held captive, many were tried and condemned, but only 39, convicted of specific acts, were executed; the others were finally released. Many bands fled into Dakota territory, and the war, disease, and want largely reduced the nation. In 1863 the Minnesota Sioux were removed to Crow creek.

About 1866 treaties were made with nine bands, promising them certain annuities, to be enlarged as they should give increased attention to agriculture. An act of Feb. 11, 1863, annulled all previous treaties with the Sioux; but to the innocent bands a part of the amount pledged was restored, the government reserving compensation for damages. The most guilty bands fled north, and are still in the British territory. A few bands continued longer in hostility, cutting off Lieut. Fetter-man and his party in December, 1866, and besieging for a time Fort Phil Kearny. In 1874 the Dakotas comprised the Santee Sioux in the reservation at the mouth of the Niobrara, Nebraska, numbering 791, with five schools under the care of the Episcopalians and the American board; the Yankton Sioux on the Missouri, with the same missionaries; the Sis-setons and the Wahpetons at Lake Traverse and Devil's lake; the Oncpapas, Blackfeet Sioux, Lower and Upper Yanktonais, Sans Arcs, Upper and Lower Brules, Two-Kettle, Minneconjous, and Ogallalas in the Crow creek, Grand river, Whetstone, Cheyenne river, and Red Cloud agencies, 46,342 in all, in Dakota; Santee, Yanktonais, Oncpapa, and Cuthead Sioux at Milk river agency, Montana, 5,309. In 1873 the government liabilities to the Dakota tribes, including payments not yet due, were estimated at $10,387,800, with annual payments for their benefit of $27,400. A treaty hastily made by Gen. Sherman, April 29, 1868, was unsatisfactory on both sides; and as gold had been discovered in the Black hills, the United States wished to purchase the tract, and induce the Sioux to abandon their hunting grounds south of the Niobrara, or even to emigrate to the Indian territory.

The Sioux showed great reluctance to treat. Sitting Bull, Red Cloud, and Spotted Tail, with other chiefs, visited Washington in May, 1875, but President Grant could not induce them to sign a treaty. Commissioners deputed by him met an immense gathering of the Sioux at the Red Cloud agency in September; but as the Sioux set an exorbitant price on their lands, the negotiation failed. Hostile feelings have been excited by alleged frauds at the Sioux agencies, which have been investigated, but as yet (1876) without result. - Much attention has been given to the Dakota language. A very good grammar and dictionary by Riggs have been issued by the Smithsonian institution. The missionaries have also supplied portions of Scripture, hymns, catechisms, and educational works in it, and newspapers issue lighter reading. It lacks the sounds f, r, v, but has peculiar sounds of its own.