You may have heard of Frank Sinatra. He was an American singer, actor, and producer who was one of the most popular and influential musical artists of the 20th Century. He is one of the best-selling music artists of all time, having sold more than 150 million records worldwide. But this famous artist had a dark secret connected to organized crime. The FBI tracked Sinatra for over 40 years amassing a dossier of thousands of pages about his movements, words, and friendships. During his rise to fame in the 1940s, Sinatra attracted the attention of the FBI for claims that he had paid a doctor $40,000 to declare him medically unfit for World War II. Though Sinatra always denied involvement in organized crime, he did interact with various famous Mafia figures such as Chicago mob boss Sam Giancana. Sinatra, it seemed, could attract the attention of conspiracy theorists and bobbysoxers with the same crooning voice—and through his career, FBI agents listened as intently as his closest fans.