On May 10, 1924, President Calvin Coolidge appointed J. Edgar Hoover to the position of director of the Federal Bureau of Investigation.

Hoover obtained a law degree from George Washington University and began working with the Justice Department during World War I. He proved to be very capable and was soon promoted to head of the Enemy Aliens Registration Section. In 1919, he became head of the new General Intelligence Division of the Justice Department. In 1921, he joined the FBI as deputy head, and in 1924, the Attorney General made him the acting director. On May 10, 1924, Hoover was appointed by President Calvin Coolidge to be the sixth director of the Bureau of Investigation.

Hoover was appointed following President Warren Harding's death, as new President Coolidge felt he needed to respond to allegations that the prior director, William J. Burns, was involved in bribery and political corruption.

Hoover had a reputation for firing FBI agents who he disliked. He also relocated agents who had displeased him to career-ending assignments and locations. Still, Hoover was an effective director and had success dealing with gangs and the Mafia. He remained director until his death in 1972.