From Grand Portage to Fort William

Until the end of the 1700s, the Nor'Westers continued to use the old French route to the west through Grand Portage and the Pigeon River. Grand Portage evolved into a major depot for transhipping goods and furs and became a rendezvous place for Montreal merchants and wintering trading partners.

The peace treaty of 1783, which the War of American Independence, made Pigeon River the border between the United States and British North America. Although Grand Portage was now within U.S. territory, it remained the Lake Superior depot for the Montreal fur trade for another twenty years. But in 1800, the threatened imposition of customs duties on all British goods moving across the Portage finally forced the traders to transfer their operations to British soil.

By 1801, the rival North West and New North West (XY) companies were each constructing separate establishments on the north bank of the Kaministikwia River, not far from the sites of the old French forts. In 1803, the North West Company held its first annual meeting at its new fort which it called "Kaministiquia." Following the amalgamation agreement of 1804, the acreage of "Kaministiquia" (as was spelled in the documents of that year) was extended to include the short-lived XY post. In 1807, the inland headquarters of the North West Company was renamed Fort William in honour of William McGillvray, chief superintendent of the Company.