Note I-5 — Chapter I · ITINERARY: ST. LOUIS TO ST. PAUL, AUGUST 9TH-SEPTEMBER 21ST, 1805.

First great tributary of the Miss. r. above the Mo. r., falling in at Calhoun pt., Calhoun Co., Ill., opp. Camden, Jersey Co., Ill.; Mason's isl. the largest one of several more in the Miss. r. just below the mouth of the Ill. r. In coming S. the Miss. r. makes a great bend E. and then nearly N. to the confluence, whence it turns again to a course approx. coincident with that which the Ill. r. holds; hence Pike's remark that the one might be mistaken for a part of the other. The river has had many names; the present is in form a French plural, sc. Rivière des Illinois, sc. of the people who lived on it—Illin, Illini, Illinoct, Illinoac, Illinoet, Illiniwek, Illeni, Illenois, Ilinois, Islinois, Islenois, etc. Pike's map has Illenois; Franquelin's, 1688, R. des Ilinois. Another aboriginal name, Theakiki, Teakiki, etc., whence Kankakee, was applied to one of the branches of this river. The Ill. r. sometimes shared the name St. Louis with the Mississippi and the Ohio. It was called R. de Seignelay by Hennepin, in compliment to the marquis of that name; and once known as the Divine r. The importance of this river as a water-way from the Great Lakes to the Mississippi is second only to that of the Wisconsin, and would be first if the long projected connection of St. Louis with Chicago by water were made. The use of these two rivers for this purpose was originally almost simultaneous; for Joliet and Marquette reached the Miss. r. from Green bay by the Wisc. r. June 15th or 17th, 1673, came down the Miss. r. past the mouth of the Ill. r. in July that year, continued down to or near the Arkansaw, turned up the Miss. r. July 17th, reached the Ill. r., and went up the latter to L. Michigan, Aug.-Sept., 1673. One of Joliet's maps, 1674, clearly shows the Wis. r. and Ill. r. connections of the Miss. r. with L. Michigan and Green bay respectively. Michael Accault's party, consisting of himself, Antoine Auguelle, and L. Hennepin, dispatched by La Salle from Fort Crêvecœur on the Ill. r., Feb. 29th, 1680, reached its mouth Mar. 7th, 1680; La Salle did the same himself Feb. 6th, 1682. The latter—one of the very greatest men in the early history of American discovery and exploration—came upon the Ill. r. in Dec., 1679, and made the first French establishment on Lower Mississippian waters in Jan., 1680, at the Illinois village Pimetoui, close to present Peoria.