William Macomb (c. 1751 – April 16, 1796) was a British colonial merchant and fur trader in the Detroit, Michigan area before and after the American Revolutionary War.
With his older brother, Alexander, William also went into fur trading in upstate New York, dealing with the six nations of the Iroquois and other tribes around the southern part of the Great Lakes.
In 1774 the brothers moved to Detroit (now Michigan, USA) as agents for Phyn & Ellice, fur traders in Schenectady, who sold them their stock for that site.
During the American Revolutionary War, the Macombs continued to supply the British at Fort Detroit and the Indian Department, becoming wealthy and highly influential, and taking another partner.
William Macomb continued to lead their business in the Detroit area, forming many connections with other British military and civil authorities.
However, this was officially discouraged by local Catholic leaders and John Graves Simcoe, the first Lieutenant Governor of Upper Canada, the jurisdiction established in 1791 after the United States gained independence.
[1] Macomb died at Detroit two months before the British evacuation of the fort in July 1796, following the settlement of the border between Canada and the United States by the Jay Treaty, which was ratified in 1795.