The Erie Canal's Economic Transformation

The Erie Canal, completed in 1825 after eight years of construction, connected the Hudson River to Lake Erie and opened a water route from the Atlantic Ocean to the Great Lakes. The 363-mile canal cut the cost of shipping goods from the Midwest to the coast by 95% and reduced travel time from three weeks to eight days. The economic transformation was immediate and enormous. New York City's population tripled in the following decade, and the canal generated enough toll revenue to pay back its entire construction cost within 12 years. It made New York the commercial capital of the United States and its effects shaped the national economy for a century.

Source: Wikipedia