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. It was constructed between 1931 and 1936 during the Great Depression and 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 one hundred lives. It was referred to as Hoover Dam after President Herbert Hoover in bills passed by Congress during its construction, but was named Boulder Dam by the Roosevelt administration. The Hoover Dam name was restored by Congress in 1947.

Since about 1900, the Black Canyon and nearby Boulder Canyon had been investigated for their potential to support a dam that would control floods, provide irrigation water and produce hydroelectric power. In 1928, Congress authorized the project. The winning bid to build the dam was submitted by a consortium named Six Companies, Inc., which began construction of the dam in early 1931. Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and lack of facilities near the site also presented difficulties. Nevertheless, Six Companies turned the dam over to the federal government on March 1, 1936, more than two years ahead of schedule.

Hoover Dam impounds Lake Mead, the largest reservoir in the United States by volume when full. The dam is located near Boulder City, Nevada, a municipality originally constructed for workers on the construction project, about 30 mi (48 km) southeast of Las Vegas, Nevada. The dam's generators provide power for public and private utilities in Nevada, Arizona, and California. Hoover Dam is a major tourist attraction; nearly a million people tour the dam each year. The heavily traveled U.S. Route 93 (US 93) ran along the dam's crest until October 2010, when the Hoover Dam Bypass opened.

Henry John Kaiser (May 9, 1882 – August 24, 1967) was an American industrialist who became known as the father of modern American shipbuilding. Prior to World War II, Kaiser was involved in the construction industry; his company was one of the companies that built Hoover Dam. He established the Kaiser Shipyards, which built Liberty ships during World War II, after which he formed Kaiser Aluminum and Kaiser Steel. Kaiser organized Kaiser Permanente health care for his workers and their families. He led Kaiser-Frazer followed by Kaiser Motors, automobile companies known for the safety of their designs. Kaiser was involved in large construction projects such as civic centers and dams, and invested in real estate, later moving into television broadcasting. With his wealth, he established the Kaiser Family Foundation, a nonprofit, non-partisan, charitable organization.