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 Greyhound Lines new subsidiary, named as the Great Lakes Greyhound Lines, which in 1941 took over the EMM. In 1941, when the Great Lakes GL came into existence, The Greyhound Corporation merged the Ohio GL into the new Great Lakes GL. The Ohio GL had run between Detroit and Louisville (in Kentucky) via Toledo, Dayton, and Cincinnati (all three in Ohio), plus along a detached route between Evansville and Indianapolis (both in Indiana). [The route segment between Louisville and Cincinnati had come from the Southland Transportation Company, which Harris Spearin, with the backing and financing of Wickman in Minnesota, had founded in