The New Student's Reference Work/Illinois Indians
Illinois Indians, the name of a community of tribes of Indians related to the great Dakota family, which inhabited the territory now comprised in the state of Illinois and also tracts of land west of the Mississippi River. They principally were Algonquins. History tells us that they were a brave, war-like race, who aided the French in their Indian wars, and fought the Sacs and Foxes on their own account. There still is a small part of the tribe on a reservation in Indian Territory.