Father Charlevoix's portrait appears to us somewhat too black, and he does not seem to estimate at its true value the great discovery which we owe to Cavelier de la Sale; a discovery, which has nothing like it, we do not say equal to it, except that of the river Amazon, by Orellana, in the 16th century, and that of the Congo, by Stanley, in the 19th. However this may be, no sooner had he arrived in the country, than he set himself, with extraordinary application, to study the native idioms, and to associate with the savages in order to render himself familiar with their manners and habits. At the same time he gathered from the trappers a mass of information on the situation of the rivers and lakes. He communicated his projects of exploration to M. de Frontenac, who encouraged him, and gave him the command of a fort constructed at the outlet of the lake into the St. Lawrence. In the meantime, one Jolyet arrived at Quebec. He brought the news that in company with Father Marquette and four other persons, he had reached a great river called the Mississippi, flowing towards the south. Cavelier de la Sale very soon understood what advantage might be derived from an artery of this importance, especially if the Mississippi had, as he believed, its mouth in the Gulf of Mexico. By the lakes and the Illinois, an affluent of the Mississippi, it was easy to effect a communication between the St. Lawrence, and the Sea of the Antilles. What marvellous profit would France derive from this discovery! La Sale explained the project which he had conceived to the Count of Frontenac, and obtained from him very pressing letters of recommendation to the Minister of Marine. On arriving in France, La Sale learned the death of Colbert; but he remitted to his son, the Marquis of Seignelay, who had succeeded him, the despatches of which he was the bearer. This project, which appeared to rest upon solid foundations, could not fail to please a young minister. Accordingly, Seignelay presented La Sale to the king, who caused letters of nobility to be prepared for him, granted him the Seignory of Catarocouy, and the government of the fort which he had built, with the monopoly of commerce in the countries which he might discover.

La Sale had also found means to procure the patronage of the Prince de Conti, who asked him to take with him the Chevalier Tonti, son of the inventor of the Tontine, in whom he felt an interest. He was for La Sale a precious acquisition. Tonti, who had made a campaign in Sicily, where his hand had been carried off by the explosion of a grenade, was a brave and skilful officer, who always showed himself extremely devoted.

La Sale and Tonti embarked at Rochelle, on July 14th, 1678, carrying with them about thirty men, workmen and soldiers, and a Recollet (monk), Father Hennepin, who accompanied them in all their voyages.

Then La Sale, being conscious that the execution of his project required more considerable resources than those which were at his disposal, constructed a boat upon the Lake Erie, and devoted a whole year to scouring the country, visiting the Indians, and carrying on an active trade in furs, which he stored in his fort of Niagara, while Tonti pursued the same course in other directions. At length, towards the middle of August, of the year 1679, his boat, the Griffon, being prepared for sailing, he embarked on the Lake Erie, with thirty men, and three Fathers, Recollets, for Machillimackinac. In crossing the lakes St. Clair and Huron, he experienced a violent storm, which caused the desertion of some of his people, whom, however, Tonti brought back to him. La Sale arrived at Machillimackinac, and very soon entered the Green Bay. But during this time his creditors at Quebec had sold all that he possessed, and the Griffon, which he had despatched, laden with furs, to the fort of Niagara, was either lost or pillaged by the Indians; which of these took place has never been precisely ascertained. For himself, although the departure of the Griffon had displeased his companions, he continued his route, and reached the river St. Joseph, where he found an encampment of Miamis, and where Tonti speedily rejoined him. Their first care was to construct a fort on this spot. Then they crossed the dividing line of the water between the basin of the great lakes, and that of the Mississippi; they subsequently reached the river of the Illinois, an affluent on the left of that great river. With his small band of followers, upon whose fidelity he could not entirely depend, the situation of La Sale was critical, in the midst of an unknown country, and among a powerful nation, the Illinois, who, at first allies of France, had been prejudiced and excited against us by the Iroquois and the English, jealous of the progress of the Canadian colony.