The St. Lawrence Seaway opened in 1959, providing a direct route for ships from the Atlantic Ocean to the Great Lakes and transforming regional trade.

The St. Lawrence Seaway, completed in 1959, revolutionized North American trade by allowing ocean-going ships to reach the Great Lakes. This joint project between the United States and Canada included a series of locks, canals, and channels stretching from the Atlantic Ocean to Lake Superior. Opening the Seaway enabled efficient transport of goods like grain, iron ore, and coal, fueling economic growth and creating new trade opportunities in the U.S. Midwest and Canadian regions. Its completion marked a pivotal shift in maritime commerce, connecting global markets to the Great Lakes and transforming both regional economies and international shipping routes.