"The Valachi Papers" is a non-fiction book written by Peter Maas that details the life of Joseph Valachi, a former member of the Genovese crime family. Published in 1968, the book reveals Valachi's experiences in organized crime and his decision to become a government informant, providing insights into the inner workings of the Mafia. The book is based on Valachi's testimony before a Senate committee in 1963, where he exposed the structure and operations of the American Mafia. It highlights the violent and secretive nature of organized crime, making it a significant work in understanding the history of the Mafia in the United States.