William G. Sebold
William G. Sebold (Gottlieb Adolf Wilhelm Sebold ; March 10, 1899 in Mülheim, Germany – February 16, 1970 in Napa, California) was a United States citizen who was coerced into becoming a spy when he visited Germany after being pressured by several high-ranking Nazi members. He informed the American Consul General in Cologne before leaving Germany and became a double agent for the FBI. With the assistance of another German agent, Fritz Duquesne, he recruited 33 agents that became known as the Duquesne Spy Ring. In June 1941, the Federal Bureau of Investigation arrested all of the agents. They were convicted and sentenced to a total of 300 years in prison. Early life Sebold served in the German army engineering corps during World War I. After emigrating to the United States in 1922, he married and worked in industrial and aircraft plants throughout the United States and South America. On February 10, 1936, he became a naturalized citizen of the United States. He returned to Germany in February 1939 to visit his mother in Mülheim. Upon his arrival in Hamburg, Germany, he was approached by a Gestapo agent who said that Sebold would be contacted in the near future due