Grand River Naval Depot 1815
In 1815 the Royal Navy began building a depot on the present site of Port Maitland. Though intended in the event of war to accommodate three frigates and 1,000 men, the base actually supported only the four schooners which then made up the British naval force on Lake Erie. The Rush-Bagot Agreement (1817) between Britain and the United States severely limited naval armament on the Great Lakes, and the depot was thereafter staffed by small detachments of soldiers. The wharf and four buildings were washed away in a storm in 1827, and the remaining buildings had largely fallen into ruin by 1834, when the establishment was abandoned.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.