Piegan Blackfeet in the context of "Mountain Chief"

The Blackfoot Confederacy, Niitsítapi, or Siksikáí'tsitapi (ᖹᒧᐧᒣᑯ, meaning "the people" or "Blackfoot-speaking real people"), is a historic collective name for linguistically related groups that make up the Blackfoot or Blackfeet people: the Siksika ("Blackfoot"), the Kainai ("Many Chiefs") or Blood, and two sections of the Peigan or Piegan or Piikani ("Splotchy Robe") – the Northern Piikani (Aapátohsipikáni) and the Southern Piikani (Amskapi Piikani or Pikuni). Broader definitions include groups such as the Tsúùtínà (Sarcee) and A'aninin (Gros Ventre) who spoke quite different languages but allied with or joined the Blackfoot Confederacy.

Historically, the member peoples of the Confederacy were nomadic bison hunters and trout fishermen, who ranged across large areas of the northern Great Plains of western North America, specifically the semi-arid shortgrass prairie ecological region. They followed the bison herds as they migrated between what are now the United States and Canada, as far north as the Bow River. In the first half of the 18th century, they acquired horses and firearms from white traders and their Cree and Assiniboine go-betweens. The Blackfoot used these to expand their territory at the expense of neighboring tribes.

The Blackfeet Nation (Blackfoot: Aamsskáápipikani / ǎmssk̇ǎaṗiiṗiik̇ǔni, Pikuni / ṗiik̇ǔni), officially named the Blackfeet Tribe of the Blackfeet Indian Reservation of Montana, is a federally recognized tribe of Siksikaitsitapi people with an Indian reservation in Montana. Tribal members primarily belong to the Piegan Blackfeet (Ampskapi Piikani) band of the larger Blackfoot Confederacy that spans Canada and the United States.

The Blackfeet Indian Reservation is located east of Glacier National Park and borders the Canadian province of Alberta. Cut Bank Creek and Birch Creek form part of its eastern and southern borders. The reservation contains 3,000 square miles (7,800 km), twice the size of the national park and larger than the state of Delaware. It is located in parts of Glacier and Pondera counties.

The Marias Massacre (also known as the Baker Massacre or the Piegan Massacre) was a massacre of Piegan Blackfeet Native peoples committed by United States Army forces under Major Eugene Mortimer Baker as part of the Indian Wars. The massacre occurred on January 23, 1870, in Montana Territory. Approximately 200 Native people were killed, most of whom were women, children, and older men.

As part of a campaign to suppress Mountain Chief's band of Piegan Blackfeet, the U.S. Army attacked a different band led by Chief Heavy Runner, to whom the United States government had previously promised their protection. This resulted in public outrage and a long-term shift towards a "Peace Policy" by the Federal Government, as advocated by President Ulysses S. Grant. Grant kept the Bureau of Indian Affairs as a division of the Department of the Interior although the War Department was trying to regain control. He then appointed men recommended by various religious clergy—including Quakers and Methodists—as Indian agents, in hopes that they would be free of the corruption he had previously found in the department.

A tipi or tepee (/ˈtiːpi/ TEE-pee) is a conical lodge tent that is distinguished from other conical tents by the smoke flaps at the top of the structure, and historically made of animal hides or pelts or, in more recent generations, of canvas stretched on a framework of wooden poles. The loanword came into English usage from the Dakota and Lakota languages.

Historically, the tipi has been used by certain Indigenous peoples of the Plains in the Great Plains and Canadian Prairies of North America, notably the seven tribes of the Sioux, as well as among the Iowa people, the Otoe and Pawnee, and among the Blackfeet, Crow, Assiniboines, Arapaho, and Plains Cree. They are also used west of the Rocky Mountains by Indigenous peoples of the Plateau such as the Yakama and the Cayuse. They are still in use in many of these communities, though now primarily for ceremonial purposes rather than daily living. Modern tipis usually have a canvas covering.