 The most important commercial enterprise in the early part of the territorial era was the lucrative fur trade . At the beginning of the 19th century two British companies competed for dominance in the North American trade : Hudson 's Bay Company and the North West Company . The North West company had used Grand Portage as its western headquarters along with other smaller companies that operated in the area . Grand Portage was one of the four principal British trading and shipping points furs in North America . Following the Treaty of Paris , in 1783 , British operations at Grand Portage were technically illegal though the trade continued . However , beginning in 1801 the North West Company began re @-@ establishing its headquarters north of the border at the newly constructed Fort William in what is now Ontario . After 1804 Grand Portage had been reduced to a minor trading center and most traders eventually abandoned the area . In 1842 , the Hudson Bay Company , which had by then absorbed the North West Company , shipped out a final band of Ojibwe who were employed by the company . 
