Federal Bureau of Investigation

Federal Bureau of Investigation (FBI), investigative branch of the U.S. Department of Justice. Established in 1908, the FBI is responsible for the investigation of possible violations of all federal laws except those for which enforcement is specifically assigned to another agency. The bureau is also concerned with internal security, counterespionage, organized crime, and corruption. FBI history was dominated by J. Edgar Hoover, director 1924–72, a conservative figure who held the post until his death. Its first permanent director after Hoover was Clarence M. Kelley, who served 1973–78 and modernized the bureau's procedures. William H. Webster, ex-federal judge and FBI director (1978–87), restructured the bureau in the light of revelations that its agents had committed illegal acts during Hoover's tenure. His tenure was followed by appointment in 1987 of William Sessions.