who authorized the construction of the boulder dam
Hoover Dam On December 21, 1928 President Coolidge signed the bill authorizing the dam.[21] The Boulder Canyon Project Act appropriated $165Â million for the Hoover Dam along with the downstream Imperial Dam and All-American Canal, a replacement for Beatty's canal entirely on the U.S. side of the border.[22] It also permitted the compact to go into effect when at least six of the seven states approved it. This occurred on March 6, 1929 with Utah's ratification; Arizona did not approve it until 1944.[23]