almost 50 years (47 years exactly)
J. Edgar Hoover was director of the FBI for 37 years, from July of 1935 to May of 1972.
J. Edgar Hoover would often relocate agents who had displeased him to career-ending assignments and locations. Melvin Purvis was a prime example; he was one of the more effective agents in capturing...
It is because of Hoover's long and controversial reign that FBI directors are now limited to 10-year terms.
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