History of Arizona programs. Federal money started arriving with the Federal Emergency Relief Committee in 1930. Different agencies promoted aid to the unemployed, tuberculosis patients, transients, and illegal immigrants. The money ran out by 1931 or 1932, and conditions were bad until New Deal relief operations began on a large scale in 1933. Construction programs were important, especially Hoover Dam (originally called Boulder Dam), begun by President Herbert Hoover. It is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border with Nevada. It was constructed by the Federal Bureau of Reclamation between 1931 and 1936. It operationalized
Colorado River beyond Yuma, Arizona, and the confluence with the intermittent Gila River – which carries runoff from western New Mexico and most of Arizona – before defining about of the Mexico–United States border. At Morelos Dam, the entire remaining flow of the Colorado is diverted to irrigate the Mexicali Valley, among Mexico's most fertile agricultural lands. Below San Luis Río Colorado, the Colorado passes entirely into Mexico, defining the Baja California–Sonora border; in most years, the stretch of the Colorado between here and the Gulf of California is dry or a trickle formed by irrigation return flows. The Hardy River provides