He spent about one year in exploring the country bordering on the lakes, and in selecting positions for forts and trading posts, to secure the Indian trade to the French. After he had built a fort at Niagara, and fitted out a small vessel, he sailed through the lakes to Green bay, then called the "Bay of Puants." From thence he proceeded with his men in canoes towards the south end of lake Michigan, and arrived at the mouth of the "river of the Miamis" in November, 1679. This is thought to be the Milwaukee in Wisconsin Territory. Here he built a fort, left eight or ten men, and passed with the rest of his company across the country to the waters of the Illinois river, and descended that river a considerable distance, when he was stopped for want of supplies. This was occasioned by the loss of a boat which had been sent from his post on Green bay. He was now compelled by necessity to build a fort, which, on account of the anxiety of mind he experienced, was called _Creve-coeur_, or broken heart. The position of this fort cannot now be ascertained; but from some appearances, it is thought to have been near Spring bay, in the northeast part of Tazewell county. At this period the Illinois were engaged in a war with the Iroquois, a numerous, warlike, and cruel nation, with whom La Salle had traded, while on the borders of Canada. The former, according to Indian notions of friendship, expected assistance from the French; but the interests and safety of La Salle depended upon terminating this warfare, and to this object he directed his strenuous efforts. The suspicious Illinois construed this into treachery, which was strengthened by the malicious and perfidious conduct of some of his own men, and pronounced upon him the sentence of death. Immediately he formed and executed the bold and hazardous project of going alone and unarmed to the camp of the Illinois, and vindicating his conduct. He declared his innocence of the charges, and demanded the author. He urged that the war should be terminated, and that the hostile nations should live in peace. The coolness, bravery, and eloquence of La Salle filled the Indians with astonishment, and entirely changed their purposes. The calumet was smoked, presents mutually exchanged, and a treaty of amity concluded. The original project of discovery was now pursued. Father Hennepin started on the 28th of February, 1680, and having passed down the Illinois, ascended the Mississippi to the falls of St. Anthony. Here he was taken prisoner, robbed, and carried to the Indian villages, from which he made his escape, returned to Canada by the way of the Wisconsin, and from thence to France, where he published an account of his travels.