Construction of the Hoover Dam began during the Great Depression in June 1933 and concluded two years ahead of schedule in September 1935. The National Historic Landmarks Program indicates that the Hoover Dam is one of the largest and earliest large-scale, multipurpose dams, providing electric power, flood control and water irrigation. The Hoover Dam is singularly responsible for increasing population and agricultural opportunity in the states of Nevada and Arizona, and 12 California municipalities including Los Angeles and Pasadena. The Hoover Dam is located in the Colorado River’s Black Canyon, straddling the border between Arizona and Nevada. Upon completion, the dam held the distinction of being the world’s largest structure, as well as the world’s largest hydroelectric power station. The Hoover Dam is named for the 31st president, Herbert Hoover, due to his efforts to get the monolith built.