St. Lawrence Seaway
St. Lawrence Seaway opened to shipping on April 25, 1959, and was formally dedicated on June 26 by Queen Elizabeth II and President Dwight D. Eisenhower, linking the Great Lakes to the Atlantic Ocean for oceangoing ships.
What happened and why it matters
The seaway let oceangoing ships reach inland ports such as Chicago, Detroit, Cleveland and Duluth, turning the Great Lakes into a direct route for international bulk trade. Built jointly by Canada and the United States, it carries mostly grain, iron ore, steel and other bulk cargo rather than containers, because its locks limit ship size and the route closes for part of each winter. The project is a reminder that the waterway a shipment can use depends on vessel size, season and cargo type, the same trade-offs freight planners weigh today when choosing between coastal ports, rail and truck for Midwest freight.