On July 7, 1930, the construction of the Hoover Dam in the State of Nevada begins.
Hoover Dam was considered the largest dam of its time with a height of 726 feet and 1,244 across. It's able to hold 28,945,000 acre-feet of water from Lake Mead, once the largest reservoir in the United States.
Hoover Dam used a total of 3,250,000 cubic yards of concrete that some estimates would be enough concrete to pave a two-lane highway from San Francisco to New York. The immensely huge amount of concrete including tens of millions of pounds of steel and pipes required thousands of workers five years of hauling dirt, pouring cement, drilling, rigging tunnels and installing the turbines that provided 2,080 megawatts of hydroelectric power when it was completed on March 1, 1936.
Although the construction of Hoover Dam was completed more than 2 years ahead of schedule, a project of this magnitude was riddled with controversy over worker's pay, environmental impact on natural ecosystems and the deaths of over one hundred workers.
Today, the chronic drought that has affected the western United States has reduced the dam's reservoir size and the amount of hydroelectric power it can produce will likely be challenged in the coming months.