Great Lakes St. Lawrence Seaway Development Corporation GLS

After decades of debate, the Wiley-Dondero Act of May 13, 1954, created the Saint Lawrence Seaway Development Corporation to build the U.S. share of a deep-draft waterway with Canada. The seaway opened to shipping on April 25, 1959, and was formally dedicated on June 26, 1959, by President Eisenhower and Queen Elizabeth II. The corporation was renamed the Great Lakes St. Lawrence Seaway Development Corporation in 2020 and is led by an Administrator.

The seaway's fifteen locks lift ships from the Atlantic tides at Montreal to Lake Erie, opening a route of more than two thousand miles into the heart of the continent. The U.S. corporation operates and maintains two of them, the Eisenhower and Snell locks near Massena, New York, while a Canadian counterpart runs the rest, and the two coordinate traffic, inspections, and tolls. Ships carry mainly bulk cargo such as grain, iron ore, steel, and salt during a navigation season that typically runs from late March to late December.

Ships wider than about 78 feet cannot fit through the locks, which were sized for the vessels of the 1950s, so the largest modern container ships cannot use the seaway and traffic has never reached early projections. Supporters see it as a low-cost, low-emission route that keeps Great Lakes ports competitive, while studies of expanding the locks have repeatedly found costs too high to justify.