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
Asian carp introduced. The United States Environmental Protection Agency is also concerned about the possibility of Asian carp migrating to the Great Lakes. In 2002, the U.S. Army Corps of Engineers completed an electric fish barrier in the Chicago Sanitary and Ship Canal, the only navigable aquatic link between the Great Lakes and the Mississippi River drainage basins. The initial fish barrier was used as a demonstration project to study the design's effectiveness. Following positive results, construction began on a second, permanent barrier in 2004. In addition to the canal, the corps has identified 19 sites in five additional states, from Minnesota