_History._--Illinois is the French form of Iliniwek, the name of a confederacy of Algonquian tribes. The first exploration by Europeans was that of the French. In 1659 Pierre Radisson and Medard Chouart des Groseilliers seem to have reached the upper Mississippi. It is certain that in 1673 part of the region known as the Illinois country was explored to some extent by two Frenchmen, Louis Joliet and Jacques Marquette, a Jesuit father. Marquette, under orders to begin a mission to the Indians, who were known to the French by their visits to the French settlements in the Lake Superior region, and Joliet, who acted under orders of Jean Talon, Intendant of Canada, ascended the Fox river, crossed the portage between it and the Wisconsin river, and followed that stream to the Mississippi, which they descended to a point below the mouth of the Arkansas. On their return journey they ascended the Illinois river as far as Lake Peoria; they then crossed the portage to Lake Michigan, and in 1675 Marquette founded a mission at the Indian town of Kaskaskia, near the present Utica, Ill. In 1679 the explorer La Salle, desiring to find the mouth of the Mississippi and to extend the domain of France in America, ascended the St Joseph river, crossed the portage separating it from the Kankakee, which he descended to the Illinois, and built in the neighbourhood of Lake Peoria a fort which he called Fort Crevecoeur. The vicissitudes of the expedition, the necessity for him to return to Canada for tools to construct a large river-boat, and opposition in Canada to his plans, prevented him from reaching the mouth of the Illinois until the 6th of February 1682. After such preliminary explorations, the French made permanent settlements, which had their origin in the missions of the Jesuits and the bartering posts of the French traders. Chief of these were Kaskaskia, established near the mouth of the Kaskaskia river, about 1720; Cahokia, a little below the mouth of the Missouri river, founded at about the same time; and Fort Chartres, on the Mississippi between Cahokia and Kaskaskia, founded in 1720 to be a link in a chain of fortifications intended to extend from the St Lawrence to the Gulf of Mexico. A monument of the labours of the missionaries is a manuscript dictionary (c. 1720) of the language of the Illinois, with catechism and prayers, probably the work of Father Le Boulanger.