The Assiniboine or Assiniboin people ("stone Sioux") were originally from the Northern Great Plains of North America. Assiniboine are closely linked by language to the Stoney First Nations people of Alberta. The latter two tribes speak varieties of Nakota, a distant, but not mutually intelligible, variant of the Sioux language. The Europeans & Americans adopted names that other tribes used for the Assiniboine. The English adopted Assiniboine, used by the Canadian French colonists. The Ojibwe name was asinii-bwaan (stone Sioux). Other tribes associated "stone" with the Assiniboine because they primarily cooked with heated stones. They dropped hot stones into water to heat it to boiling for cooking meat. The Assiniboine, along with the Stoney of Alberta, share a common ancestry with the Sioux nation. The separation of the Assiniboine from the Sioux must have occurred at some time prior to 1640, as Paul Le Jeune names them along with the "Naduessi" (Sioux) in his Jesuit Relations of that year. The Assiniboine & Sioux were both gradually pushed westward onto the plains from the woodlands of Minnesota by the Ojibwe, who had acquired firearms from their French allies. Later, the Assiniboine acquired horses via raiding & trading with neighboring tribes of Plains Native Americans such as the Crow & the Sioux on their south.
The Assiniboine eventually developed into a large & powerful people with a horse & warrior culture; they used the horse to hunt the vast numbers of bison that lived within & outside their territory. At the height of their power, the Assiniboine dominated territory ranging from the North Saskatchewan River in the north to the Missouri River in the south, & including portions of modern-day Saskatchewan, Alberta, & Manitoba, Canada; & North Dakota & Montana, United States of America. The next person of European descent known to describe the Assiniboine was an employee of the Hudson's Bay Company named Henry Kelsey in the 1690s. Later explorers & traders Jean Baptiste de La Vérendrye & his sons (1730s), Anthony Henday (1754–55), & Alexander Henry the younger (1800s) confirmed that the Assiniboine held a vast territory across the northern plains, including into the United States (which achieved independence in 1783 but did not acquire the plains until 1803 in the Louisiana Purchase from France.) The Assiniboine became reliable & important trading partners & middlemen for fur traders & other Native Americans, particularly the British Hudson's Bay Company & North West Company, operating in western Canada in a vast area known then as Rupert's Land. During the later 18C & early 19C, south of the border in what became Montana & the Dakota territories, the Assiniboine traded with the American Fur Company & the competing Rocky Mountain Fur Company. The Assiniboine obtained guns, ammunition, metal tomahawks, metal pots, wool blankets, wool coats, wool leggings, & glass beads, as well as other goods from the fur traders in exchange for furs. Beaver furs & bison hides were the most commonly traded furs.
The Lewis & Clark expedition's journals mention the Assiniboine, whom the party heard about while returning from Fort Clatsop down the Missouri River. However, these explorers did not encounter or come in direct contact with the tribe. Noted European & American painters traveled with traders, explorers, & expeditions for the opportunity to paint the West & its Native American peoples. Among those who encountered & painted the Assiniboine from life were painters Karl Bodmer, Paul Kane, & George Catlin. Increased contact with Europeans resulted in Native Americans contracting Eurasian infectious diseases from the Europeans. They suffered epidemics with high mortality, most notably smallpox among the Assiniboine. The Assiniboine population crashed from around 10,000 people in the late 18th century to around 2600 by 1890.
