How long was J. Edgar Hoover in charge of the FBI? March 3, 2012 by Pamela Landy · Filed Under: People Hoover directed the Bureau of Investigation for 48 years, from 1924 until his death in 1972. The Bureau of Investigation was renamed the Federal Bureau of Investigation in 1935. Most know it as the FBI. Related PostsHow long has the FBI been in operation?Why do bulls charge when they “see red”?When was the Charge of the Light Brigade?What is the difference between Hoover Dam and Boulder Dam?Which was larger, the landslide that elected Herbert Hoover to the presidency in 1928 or the landslide that removed him in 1932?