The first major treaties made with tribes in this region were made in 1825. A group under Indian Agent Benjamin O’Fallon and General Henry Atkinson traveled up the Missouri River to the Yellowstone with nine keelboats and a large military escort, making treaties with the Teton, Yankton, and Yanktonai Dakota; Cheyenne, Mandan, Hidatsa, and Arikara. In the Atkinson and O’Fallon treaties, also known as the “Friendship Treaties” the Indians acknowledged the supremacy of the United States, which in turn promised them its protection. The tribes, along with the Mandan, Hidatsa, and Arikara agreed not to trade with anyone but authorized American citizens. They also agreed to the use of United States law to handle injury of American citizens by Indians and vice versa. (Schulenberg, 1956, p. 101) On July 18, 1825 the Arikara signed, and on July 30, the Belantse-Etoa or Minitaree Tribe (Hidatsa) and Mandan signed the Atkinson and O’Fallon Treaty.
In 1851, a tribal delegation of Mandan, Hidatsa, and Arikara (Sahnish) accompanied Father Pierre-Jean DeSmet to Fort Laramie to hold council with representatives of the government of the United States. White Wolf spoke for the Mandans, Four Bears for the Hidatsa, and Iron Bear for the Arikara. Colonel M. Mitchell and Major Fitzpatrick represented the government. The boundaries of the Mandan, Hidatsa, and Arikara territory were set-aside in the 1851 Fort Laramie Treaty:
Commencing at the mouth of the Heart River;
thence up the Missouri to the mouth of the
Yellowstone River; thence up the Yellowstone
to the mouth of Powder River, thence in a
southeasterly direction to the headwaters of
the Little Missouri River, thence along the
Black Hills to the headwaters of the Heart
River; thence down the Heart River to the place
of the beginning. (11 Stats., p. 749, in Kappler,
1972, p. 594, Article 5)
This was the largest treaty council ever held. More than ten thousand plains Indians from the Lakota, Cheyenne, Arapaho, Crow, Mandan, Arikara, Assiniboine, and Gros Ventres (Hidatsa) nations attended. In exchange for $50,000 a year for 50 years, the nations agreed to allow the United States to construct roads and military posts through their country. The tribes also established the boundaries of their territories and agreed to maintain peaceful relations with one another and with the United States. Several tribes, including the Mandans, Gros Ventres (Hidatsas), Crows, Blackfeet, and some bands of the Cheyennes and Araphaos, accepted reservations. (O’Brian, 1989, p. 141)
Under the terms of agreement, the United States would supply the several tribes with $50,000 for 50 years, designate territorial boundaries of each tribe, provide punishment for depredations, and gave authority for the government to lay roads and build military forts in Indian country and other provisions. (Kappler, (compiled and edited) 1904 Indian Affairs, Laws and Treaties, Washington, Vol. II, pp. 594-596)
When the treaty was returned to Washington, the U.S. Senate refused to give its approval to the long term financial arrangements, and amended the treaty by limiting the appropriation to ten years. The Indians were not a part of this amendment and believed the original treaty was still in force.
In this form, the Fort Laramie Treaty of 1851 was ratified by the U.S. Senate on May 24, 1852, and the amendment was not sent to the tribes until 1853. While the government secured some signatories to the amendment, in some cases under threat to withhold annuities, the amended document was never approved by all of the tribes concerned. This amendment has been a source of controversy ever since.
Following the Fort Laramie Treaty of 1851, the government established several forts along the Missouri River. In 1864 the cavalry was sent to Fort Berthold and remained there until 1867 when they moved to Fort Stevenson, 18 miles down river. The establishment of forts brought numerous groups up river by steamboat—twenty to thirty steamboats stopped at Like-A-Fishhook Village every summer. By the early 1870s, the railroad had reached the territory of the Mandan, Hidatsa, and Arikara, a bustling economic center for the region.
By 1871, federal Indian policy shifted radically for several reasons. An act of Congress in 1871 “Provided that no treaties shall hereafter be negotiated with any Indian tribe within the United States as an independent nation or people.” Thereafter, all Indian land cessions were achieved by act of Congress or by Executive Order.
Indian societies were being transformed radically from a combination of forces—U. S. Army troops stationed at posts near Fort Berthold after 1864, Indian agency personnel resided on the reservation after 1868, and day schools were being opened on reservations as early as 1870.