Thousand Islands International Bridge
This international bridge system links Canada and the United States across the St. Lawrence River and islands from Ivy Lea, Ontario, to Collins Landing, N.Y. It was opened on August 18, 1938, by William Lyon Mackenzie King, Prime Minister of Canada, and Franklin Delano Roosevelt, President of the United States. The crossing was financed and constructed by the Thousand Islands Bridge Authority, a public body created by New York State in 1933, which operates and maintains it. Five bridges of four different types - two-span continuous truss, steel arch, stone-faced concrete rigid frame, and two suspension- with approaches and connecting viaducts and highways cover a distance of about 13 km.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.