Chicago used to ship to the coast through the Great Lakes. The Erie Canal connected the Great Lakes to the Hudson River, and that trade made both New York and

Chicago used to ship to the coast through the Great Lakes. The Erie Canal connected the Great Lakes to the Hudson River, and that trade made both New York and Chicago what they are today. But railroads became a thing and they just built a new one that followed the same route as the canal. You can also ship down to the Mississippi from Chicago, but again you're dependent on a canal to bridge the gap to the navigable waterways.