sentences:  Though their use has diminished somewhat with the arrival of rail transportation, the Interstate Highway/400 series highways networks of America and Canada, and with the debut of air travel, they are still widely used for transporting goods from the American Midwest to overseas markets.The cities of Duluth, Minnesota and Thunder Bay, Ontario (to some extent, Chicago, Illinois as well) are the most inland seaports/deepwater ports in the world, being well over 2000 miles from the shores of the Atlantic Ocean, yet they still can cater to cargo ships, thanks to the St. Lawrence Seaway, Welland Canal and Soo Locks, a joint-venture binational system of dams, locks, and canals built by Canada and the United States in 1959.The Mississippi/Missouri River system also sees a large amount of oceanbound ship traffic from cities such as St. Louis, Kansas City, and New Orleans.