Great Lakes passenger steamers the lakes grew in size and number, and additional decks were built on the superstructure to allow more capacity. This inexpensive method of adding capacity was adapted from river steamboats and successfully applied to lake-going craft. The Erie Canal opened in 1825, allowing settlers from New England and New York to reach Michigan by water through Albany and Buffalo. This route opening and the incorporation of Chicago in 1837, increased Great Lakes steamboat traffic from Detroit through the straits of Mackinaw to Chicago. The screw propeller was introduced to the Great Lakes by "Vandalia" in 1842 and allowed the building
Great Lakes region area urban planners call the Great Lakes Megalopolis, which has an estimated 59 million people. Chicago is emerging as the third megacity in the United States, after the New York City and Los Angeles metropolitan areas, with a metro population approaching ten million. Cities along the Great Lakes have access to the Atlantic Ocean through the St. Lawrence Seaway, making them international ports. The Palaeozoic strata, are but parts of a great area of similar strata hundreds of feet in thickness. These strata decline gently southward from the great upland of the Laurentian Highlands of eastern Canada. The visible upland