The Capture of Fort William
In 1812, the Earl of Selkirk settled dispossessed Scottish highlanders on Red River valley lands granted by the Hudson's Bay Company. The HBC's rival in the fur trade, the North West Company, feared the new colony would block its trade and supplies. Clashes between traders and colonists culminated with the killing of twenty settlers in the Massacre of Seven Oaks on June 19, 1816. News of Seven Oaks reached Selkirk as he was travelling westward with Swiss mercenaries hired to defend the colony. On August 13, he seized Fort William, the Nor'Westers' inland headquarters, and arrested several senior partners. A bitter court battle ensued. The incident contributed to the British government's decision to pressure the two fur trade companies to merge in 1821.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.