Thus, in 1682, La Salle had secured an empire for France, and at last found a legitimate field for his own ambition. His Louisiana comprised every thing between the Alleghanies and Rio Grande, the Gulf of Mexico and Hudson's Bay. Upon opening the maps of the time we find the English crowded into the comparatively narrow limits extending from the eastern slopes of the Appalachian range to the sea, the Spaniards occupying those between the Rio Grande and Gulf of California, while the whole great heart of the continent, including portions of Carolina and Florida, with its magnificent system of waterways, is covered by the names New France and Louisiana. But La Salle himself, the man of large and luminous views, had now reached the high-water-mark of his achievements. The wave which owed its impetus to his active brain, expended its force with his life. Upon his return voyage up the Mississippi the explorer fell sick. He was taken to Fort Prudhomme, the one built by his order on the way down, where he lay for months a helpless invalid, chafing under the inaction thus forced upon him. As soon as he felt strong enough to bear the journey, La Salle proceeded on to Michilimackinac, where he was no sooner arrived than he set about the work of rebuilding the trading-post on the Illinois, in room of the one his treacherous followers had destroyed in his absence. This was to be his half-way house to the Mississippi. Here he trusted to gather a colony alike capable of drawing to itself all the trade of a vast tributary region, as of defending itself and his allies, the Illinois, against the incursions of the Iroquois. But La Salle's greater project for securing the results of his discoveries, by planting a colony at the mouth of the Mississippi, henceforth looked to reaching that point by sea and not by land. To transport every thing overland from Quebec to the Gulf was of course impracticable. No one knew this better than La Salle himself, yet he also foresaw the importance of keeping the way to Canada open if the colony at the Gulf was to thrive. To this end the fort on the Illinois, and that at the Chickasaw Bluff, were but incidents. After establishing himself strongly on the Illinois, La Salle went to France in order to lay his projects before the King. In consequence of a rupture with Spain he found the court well disposed to listen to his proposals. These contemplated the building of a fort sixty leagues above the mouth of the Mississippi, which La Salle assumed would draw around it, as to a common centre, all the neighbor tribes. Gifts and good usage had already disposed these tribes favorably toward the French, while the Spaniards had already alienated them by harsh treatment. With their help La Salle asserted that the conquest of New Biscay,[1] with its rich silver-mines, would be an easy matter, because there were not more than four hundred Spaniards in all that province.