High Quality Content by WIKIPEDIA articles! Nathan Gregory Silvermaster (November 27, 1898 – October 7, 1964), an economist with the United States War Production Board (WPB) during World War II, was the head of a large ring of Communist spies in the U.S. government. It is from him that the FBI Silvermaster File , documenting the Bureau`s investigation into Communist penetration of the Federal government during the Cold War, takes its name. His wife, Helen and stepson, Anatole Volkov, were members of his ring.