Evidently, Hoover amassed significant power by collecting files on people, especially politicians, that were kept off of the official FBI records. This unofficial legacy is speculative because his secretary of decades, (Miss) Helen Gandy, spent the days after Hoover's death destroying all of these files.
Speculation that Hoover practiced homosexuality has never been confirmed with factual evidence. Hoover was raised a devout Presbyterian, considered the ministry as a career, and used this publically known fact to render his personal conduct, sexually or otherwise, unimpeachable during his tenure at the FBI. President Richard Nixon's comment's on hearing that Hoover had just passed away ("That old cocksucker? We thought he was immortal.") cannot be taken literally, due to Nixon's well-documented prediliction for prevarication.