The Illinois Confederation, sometimes referred to as the Illiniwek or Illini, was a group of 12-13 Native American tribes in the upper Mississippi River valley of North America. The tribes were the Kaskaskia, Cahokia, Peoria, Tamaroa, Moingwena, Michigamea, Chepoussa, Chinkoa, Coiracoentanon, Espeminkia, Maroa, and Tapouara. At the time of European contact in the 17th century, they were believed to number over 10,000 people. Most of the Illinois spoke various dialects of the Miami-Illinois language, one of the Algonquian languages family, with the known exception of the Siouan-speaking Michigamea. They occupied a broad inverted triangle from modern-day Iowa to near the shores of Lake Michigan in modern Chicago south to modern Arkansas. By the mid-18th century, only five principal tribes remained: the Cahokia, Kaskaskia, Michigamea, Peoria, and Tamaroa.
Illinois was not the tribes' name for themselves, or autonym. Rather, Illinois is a French transliteration of an Old Ottawa term for them, or exonym: /ilinwe/ (pl. /iliniwek/). (The Ottawa were a neighboring tribe, whom the French met first.) Ilinwe is in turn an Odawa language rendering presumably borrowed from the Illinois or Old Miami verb /irenweewa/, iren(i)we·wa or ileenwewa (?he speaks the ordinary way? or ?he speaks our language?, ?he speaks like us?), because they could easy understand each other. One other source is probably the Miami-Illinois word /irenawaki/, /ilenawaki/ (?the true (irena or ilena) ones (waki)?) or aleniaki (Sing: alenia - ?Person?, ?People?). Sometimes it is suggested that the tribal name comes from the term which the ,,Illinois/Inoca" used to designate their language - ireniweeyoni or iilinwiyankwi (?Our language?, lit. ?the ordinary, real language?).
Unlike the plural form iliniwek, the term illini does not appear to have a historic linguistic connection.
Among the earliest renditions of the modernized, Anglicized term "Illiniwek" were Liniouek (1656), "Aliniouek" (1658), "Alimiwec" (1660), "irini?ak" (1662; the old French symbol ?, often printed as the numeral '8' which it resembles, represents the vowel /o/ in Illinois), and "Ilinioüek" (1667). In 1670 Father Claude Allouez, S.J. referred to a band of natives as "IlimoucK" (the editor added an alternative spelling "Iliniouek") in one sentence and "Ilinioüetz" in the next. The English translation changed the latter spelling to "Iliniouetz." In the variable spelling of the times, the name of Allouez was also spelled "Alloues," "Alloez," Aloes," "Aloez," "Aloues," and "Daloes" in these early records.
The ,,Illinois/Inoca" autonym was /Inoca/, /Inoka/ or /Inouca/ (currently of unknown meaning), as it appears in all three Illinois dictionaries from the late 17th/early 18th century. For example, in the Illinois-French dictionary from the early 18th century often attributed to Gravier, the word 'In?ca' is translated as Illinois people. Or, in the 1725 LeBoullenger French-Illinois dictionary, the same word is spelled inoca, and translated Illinois.
The terms Illini (singular) and lliniwek, Illiniwek (plural) are therefore common in (historical) and current literature - and to designate the political organization of the ,,Illinois/Inoca" it is currently customary to name these Illinois Confederation.
When French explorers first journeyed to the region from Canada in the 17th century, they found the area inhabited by a vigorous, populous, Algonquian-speaking nation. What we know today about the Illinois is based on the historical account Jesuit Relations, written by French Jesuits. The missionaries who lived among the various native nations wrote the Relations and sent the reports back to their superiors in France. One name for an Illinois Confederation tribe, the Cahokia, was used as a name for a French settlement, now Cahokia, Illinois, near what are now called the Cahokia Mounds, the remains of a large pre-Columbian city. However, it is currently unknown whether the Illinois Confederation peoples, including the Cahokia, have any relationship to the earlier native builders of the mounds civilization.
In the 17th century, the Illinois suffered from a combination of exposure to Eurasian infectious diseases, to which they had no natural immunity, and warfare by the expansion of the Iroquois into the western Great Lakes region. The Iroquois had hunted out their traditional lands and sought more productive hunting and trapping areas (see, Beaver Wars). They sought furs to purchase European goods in the fur trade. Many of the Illinois migrated to present-day eastern Kansas to escape the pressure from other tribes and encroaching European settlers.
The Illinois lived in a seasonal cycle related to cultivation of domestic plants and hunting, with movement from semi-permanent villages to hunting camps. They seasonally lived in long houses and wigwams of wood and woven mats. They planted crops of maize (corn), beans, and squash, known as the "Three Sisters". They prepared dishes such as sagamite. They also gathered wild foods such as nuts, fruit, roots, and tubers. In the hunting season, the men hunted bison, deer, elk, bear, cougar, lynx, turkey, geese and duck. Women prepared the meat for preservation and the hides for equipment and clothing. They tapped maple trees and made the sap into a drink or boiled it for syrup and sugar.
As a consequence of the Indian Removal Act, in the 1830s, the Illinois were relocated from where they had migrated to in eastern Kansas to northeastern Indian Territory. Today they chiefly reside in Ottawa County, Oklahoma, as the Peoria Tribe of Indians of Oklahoma.