Illinois is the 21st State Admitted to the Union
Illinois entered the Union on December 3, 1818.
The 21st state takes its name from the Illinois Confederation—a group of Algonquian-speaking tribes native to the area. An Algonquin word, "Illinois" means "tribe of superior men."
Remnants of a much earlier civilization, thought the most sophisticated prehistoric society north of Mexico, are preserved at the Cahokia Mounds State Historic Site in the southwestern part of the state.
The Illinois-Wabash Company was an early claimant to much of Illinois. The Illinois Territory was created on February 3, 1809, with its capital at Kaskaskia. In 1818, Illinois became the 21st U.S. state. The new state debated slavery then rejected it, as settlers poured into southern Illinois from Kentucky.
Near the mouth of the river Kaskaskies, there is a village which appears to have contained near eighty families from the beginning of the late revolution. There are twelve families in a small village at la Prairie du Rochers, and near fifty families—the Kahokia village. There are also four or five families at fort Chartres and St. Philips, which is five miles farther up the river. The heads of families in those villages appear each of them to have had a certain quantity of arable land allotted to them, and a proportionate quantity of meadow and of woodland or pasture.”— The Committee…referred the memorial of George Morgan…respecting a tract of land in the Illinois