He battled the Kennedys and Martin Luther King, encouraged McCarthy and single-handedly changed the course of history. Hired by F.D.R. to be the director of the FBI, Hoover erected the most ... Read allHe battled the Kennedys and Martin Luther King, encouraged McCarthy and single-handedly changed the course of history. Hired by F.D.R. to be the director of the FBI, Hoover erected the most sophisticated investigatory agency in the world.He battled the Kennedys and Martin Luther King, encouraged McCarthy and single-handedly changed the course of history. Hired by F.D.R. to be the director of the FBI, Hoover erected the most sophisticated investigatory agency in the world.