Can ocean vessels float from the Atlantic Ocean to Chicago?

Despite being over a thousand miles from the nearest coast, Chicago functions as an international seaport. This is made possible by the St. Lawrence Seaway, a remarkable system of locks, canals, and channels that serves as a marine highway. This waterway allows vessels to travel from the Atlantic Ocean, up the St. Lawrence River, and directly into the heart of North America via the Great (Review) Lakes.

The journey requires overcoming significant changes in elevation between the Atlantic and the inland lakes. A series of massive locks act like water elevators, lifting and lowering ships from one water level to another. The most crucial part of this system is the Welland Canal, an engineering marvel that allows vessels to bypass the formidable Niagara Falls between Lake Ontario and Lake Erie, completing the link to the upper Great Lakes.

Opened in 1959 as a joint U.S.-Canadian venture, the Seaway transformed the continent's industrial heartland into a fourth seacoast. While the system is impressive, not every ocean vessel can make the trip. Ships must be built to a specific size, known as "Seawaymax," to fit through the locks, ensuring their passage all the way to the shores of Lake Michigan and the port of Chicago.