The Trent-Severn Waterway
The canalization of the waterway from the Bay of Quinte to Lake Simcoe to provide communications between Lake Ontario and the new settlements around Peterborough was proposed officially in 1827. The project was begun 1833-35 with a survey of the route and the building of a lock at Bobcaygeon. Work proceeded sporadically but by 1872 local navigation was possible on long sections of the route. After 1880 pressure increased on the federal government to complete the waterway (including an extension to Georgian Bay) as a route for traffic from the West, and the final stage of construction was begun in 1895. Opened for small boats in 1920, the Trent-Severn is one of the province's major recreational waterways.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.