President Herbert Hoover was an environmentalist so deal with it! His main focus points included pollution-free water, flood control, and fisheries. So, therefore, after a disastrous Mississippi River flood in 1927, Hoover recommitted to bettering American infrastructure to prevent another similar catastrophe. On July 7th, 1930, construction of the Hoover Dam began. Over the next five years, a total of 21,000 men would work ceaselessly to produce what would be the largest dam of its time, as well as one of the largest manmade structures in the world! Learn more about your ad choices. Visit megaphone.fm/adchoices