History of New York City (1784–1854) surged far beyond its rivals, reaching a population of 1,080,000 in 1860, compared to 566,000 in Philadelphia, 212,000 in Baltimore and 178,000 in Boston. Historian Robert Albion identifies four aggressive moves by New York entrepreneurs and politicians that helped it jump to the top of American cities. Of greatest importance, it sponsored the Erie Canal which began operations in 1825, forming a continuous water route from New York north to Albany via the Hudson River, then west to Buffalo using the new canal to reach the Great Lakes. It opened a large new market in upstate New York and the
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