J. Edgar Hoover was the first Director of the Federal Bureau of Investigation (FBI) in the United States, serving from 1935 until his death in 1972. He played a significant role in shaping the FBI into a modern crime-fighting agency and was known for his efforts in combating organized crime and espionage during the Cold War. Hoover was a controversial figure, often criticized for his use of surveillance and intelligence-gathering tactics. He was involved in various high-profile cases, including the investigation of Martin Luther King Jr. and the Civil Rights Movement. His legacy remains complex, reflecting both his contributions to law enforcement and concerns about civil liberties.