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
Rideau Canal canal to Kingston and out into Lake Ontario. The objective was to bypass the stretch of the St. Lawrence bordering New York; a route which would have left British supply ships vulnerable to an attack or a blockade of the St. Lawrence. The canal also served a commercial purpose. The Rideau Canal was easier to navigate than the St. Lawrence River because of the series of rapids between Montreal and Kingston. As a result, the Rideau Canal became a busy commercial artery from Montreal to the Great Lakes. However, by 1849, the rapids of the St. Lawrence had been tamed