Each license permitted the fitting out of two large canoes with merchandise for the lakes, and no more than twenty-five licenses were to be issued in one year.

By degrees, however, private licenses were also granted, and the number rapidly increased.
Those who did not choose to fit out the expeditions themselves, were permitted to sell them to the merchants; these employed the coureurs des bois, or rangers of the woods, to undertake the long voyages on shares, and thus the abuses of the old system were revived and continued.
The pious missionaries employed by the Roman Catholic Church to convert the Indians, did everything in their power to counteract the profligacy caused and propagated by these men in the heart of the wilderness.

The Catholic chapel might often be seen planted beside the trading house, and its spire surmounted by a cross, towering from the midst of an Indian village, on the banks of a river or a lake.

The missions had often a beneficial effect on the simple sons of the forest, but had little power over the renegades from civilization.
At length it was found necessary to establish fortified posts at the confluence of the rivers and the lakes for the protection of the trade, and the restraint of these profligates of the wilderness.

The most important of these was at Michilimackinac, situated at the strait of the same name, which connects Lakes Huron and Michigan.