Query: What made Hoover stop serving as the FBI Director?
Context: They must be confirmed by the United States Senate and serve a term of office of five years, with a maximum of ten years, if reappointed, unless they resign or are fired by the President before their term ends. J. Edgar Hoover, appointed by Calvin Coolidge in 1924, was by far the longest-serving director, serving until his death in 1972. In 1968, Congress passed legislation as part of the Omnibus Crime Control and Safe Streets Act Pub.L. 90–351, June 19, 1968, 82 Stat. 197 that specified a 10-year limit, a maximum of two 5-year terms, for future FBI Directors, as well as requiring Senate confirmation of appointees.