Boulder Dam (later Hoover Dam) begins to generate electricity and transmit it to Los Angeles.

The Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. Constructed between 1931 and 1936, during the Great Depression, it was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over 100 lives. Bills passed by Congress during its construction referred to it as Hoover Dam, but the Roosevelt administration named it Boulder Dam. In 1947, Congress restored the name Hoover Dam.

Los Angeles, often referred to by its initials L.A., is the most populous city in the U.S. state of California, and the commercial, financial, and cultural center of Southern California. With an estimated 3.88 million residents within the city limits as of 2024, it is the second-most populous in the United States, behind New York City. Los Angeles has an ethnically and culturally diverse population, and is the principal city of a metropolitan area of 12.9 million people (2024). Greater Los Angeles, a combined statistical area that includes the Los Angeles and Riverside–San Bernardino metropolitan areas, is a sprawling metropolis of over 18.5 million residents.