6. David Sheldon Boone
America will not forget Boone as one of the most popular spies in the history of the nation. Boone sold secretive documents of the National Security Agency (NSA) to the Union of Soviets for three years. (1988 to 1991). One of these documents sold to the Soviets Union was a 600-page manual that contained the full description of the reconnaissance of the United States.
It also contained a collection of nuclear targets in Russia. Boone worked in the U.S Army as a signals intelligence analyst. He joined the NSA as a cryptologic traffic analyst in 1985, giving him access to this classified information.
