Few people have had the effect on American history that J. Edgar Hoover did. As the Director of first the Bureau of Investigation and then the rechristened Federal Bureau of Investigation, Hoover managed to track, surveil, and arrest anyone he thought was a subversive who was trying to harm the United States Government. Under this rubric, Hoover would target bank robbers, communists, anarchists, mafiosos, and civil rights leaders. More importantly, he transformed a small division of the Justice Department into a separate, hugely important element of the government that was responsible for any intelligence gathering on domestic subjects. Hoover himself was a peculiar man who would rule the FBI with an iron fist. He spoke extremely fast at all times, was obsessed with data and record collection, and moved any Bureau agents he did not like out of his office. Hoover was widely loathed in the government, but no one could do anything to stop him, as he served as Director of the FBI until his death in 1972.