Opening of Saint Lawrence Seaway

Date: April 25, 1959 • Location: Montmorency County, United States

The Saint Lawrence Seaway, linking the North American Great Lakes and the Atlantic Ocean, officially opens to shipping.

The St. Lawrence Seaway is a system of rivers, locks, canals, and channels in Eastern Canada and the Northern United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North America, as far inland as Duluth, Minnesota, at the western end of Lake Superior. The seaway is named for the St. Lawrence River, which flows straight from Lake Ontario to the Atlantic Gulf of St. Lawrence. Legally, the seaway extends from Montreal, Quebec, to Lake Erie, and includes the Welland Canal. Ships from the Atlantic Ocean are able to reach ports in all five of the Great Lakes via the Great Lakes Waterway.