The chief significance of the Chicago portage to the explorers when they passed it was the view of the lake which they had as they descended the stream towards its mouth. Lake Michigan, indeed, had been discovered long before, but it was known only along its northern shores extending as far as Green Bay, which had been entered by the missionaries, a station being established at its farthest extremity. The southern extension of Lake Michigan was unknown until Joliet and Marquette paddled into it with their canoes as they left the Chicago River.
No date was mentioned by Marquette in his journal of the arrival of the party in the river, but it must have been about the beginning of September, 1673. Joliet also kept a journal, but unfortunately he lost all his papers in a canoe accident before he reached Quebec on his return. That the site of the future Chicago, situated as it was on so important a portage connecting the lake with the river systems of the interior, possessed advantages of a striking kind was plainly perceived by Joliet, who afterward wrote that an artificial waterway could easily be constructed by cutting only a half league of prairie, "to pass from the Lake of the Illinois into St. Louis River."
Thus, upon reaching the mission station of St. Francis Xavier, situated near the mouth of the Fox River, from which they had started, the explorers had completed a journey of about twenty-five hundred miles in a period of four months, had opened to the eyes of the world the wonderful river of the West, had incidentally discovered the site of the future great city of Chicago, and had made the complete circuit back to Green Bay without the loss of a man or the occurrence of a single untoward accident.
La Salle's first appearance on Lake Michigan was in September, 1679, six years after Joliet's expedition. La Salle came down through the Straits of Mackinac with a party of seventeen, skirted the western shore of the lake toward the south, but believing he could reach the Illinois River by a more favorable route than that over which Joliet had passed, he coasted around the southern end of the lake until he reached the mouth of the St. Joseph River. Ascending that river he found the portage into the Kankakee and readily made his way to the Illinois, where he established a fort near Peoria. He returned to Canada the following year, and recruiting another party he once more passed over the St. Joseph-Kankakee route to the same destination as before.
Again returning to Canada he started near the end of the year 1681 with a much larger party, and this time he chose the Chicago-Desplaines route to the interior. He continued on down the Illinois to its mouth, thence down the Mississippi, passed the farthest point reached by Joliet, and at length arrived at its mouth and issued forth upon the waters of the Gulf of Mexico. This event took place on the 7th of April, 1682.
La Salle was thus the first white man to pass down the Mississippi River from the mouth of the Illinois to the Gulf. De Soto's followers after his death had indeed returned from their ill-starred expedition by way of the lower Mississippi, but it remained for La Salle to arrive at a certain knowledge of the course taken by the river throughout the long distance over which he passed and to determine its flow into the Gulf of Mexico, and moreover to establish the first substantial claim in behalf of a European power to the soil of Louisiana.
La Salle had entered upon an extensive system of colonization, and through many dangers and difficulties he had secured footholds for the French in the western country. He passed frequently back and forth between the forts he had established and his base of supplies at Montreal. In the summer of 1683 he was in Chicago and wrote a letter to his lieutenant, Tonty, whom he had left in command of Fort St. Louis, on the Illinois River, dating the letter "Portage du Chicagou, 4 Juin, 1683." During the next three years he spent the larger part of his time in attempting to found a colony on the shores of the Gulf of Mexico, and while in the midst of his activities he was foully assassinated by some of his followers. His death occurred on March 19, 1687.
Parkman sums up the character of La Salle in this fine passage: "Serious in all things, incapable of the lighter pleasures, incapable of repose, finding no joy but in pursuit of great designs, too shy for society and too reserved for popularity, often unsympathetic and always seeming so, smothering emotions he could not utter, schooled to universal distrust, stern to his followers and pitiless to himself, bearing the brunt of every hardship and every danger, demanding of others an equal constancy joined to an implicit deference, heeding no counsel but his own, attempting the impossible and grasping at what was too vast to hold,—he contained in his own complex and painful nature the chief springs of his triumphs, his failures, and his death."