William Sebold and his wife photographed in New York City, 1937. NY Daily News.
William G. Sebold, born Gottlieb Adolf Wilhelm Sebold on March 10, 1899, in Mülheim, Germany, played a pivotal role in one of the most significant espionage cases in American history. As a double agent for the FBI during World War II, Sebold’s courageous actions led to the dismantling of the Duquesne Spy Ring, the largest Nazi spy ring ever uncovered in the United States.
Sebold served in the German army’s engineering corps during World War I. After the war, he emigrated to the United States in 1921, seeking better opportunities. He worked in various industrial and aircraft plants across the U.S. and South America, gaining valuable technical knowledge. In 1936, Sebold became a naturalized U.S. citizen, solidifying his commitment to his new homeland.
Becoming a Double Agent
In February 1939, Sebold returned to Germany to visit his mother. Upon his arrival in Hamburg, he was approached by a Gestapo agent who informed him that he would be contacted soon. This ominous encounter marked the beginning of Sebold’s coerced involvement with the Nazis. In September 1939, Dr. Gassner, a representative of the German intelligence service Abwehr, visited Sebold and pressured him to become a spy for Germany. Threats to his family and his citizenship, along with the revelation of past indiscretions, left Sebold with little choice but to comply.
Despite the coercion, Sebold’s loyalty to the United States remained unwavering. He secretly informed the American Consul General in Cologne about his predicament and expressed his willingness to cooperate with the FBI. Upon his return to the U.S. in February 1940, Sebold assumed the alias “Harry Sawyer” and began his work as a double agent. His mission was to meet with various German spies, pass along instructions from Germany, and transmit coded messages back to the Nazis.
The Duquesne Spy Ring
Under the guidance of the FBI, Sebold established a shortwave radio station in New York City, which he used to communicate with German agents. For nearly two years, the FBI ran the shortwave radio station in New York, which allowed them to monitor and control the information being sent to Germany. Sebold’s efforts led to the identification and arrest of 33 German spies, including the ringleader Fritz Joubert Duquesne. This group, known as the Duquesne Spy Ring, was responsible for espionage activities aimed at sabotaging American military and industrial targets.
The Duquesne Spy Ring was the largest espionage case in U.S. history that ended in convictions. The Nazi agents in the ring were embedded in various strategic positions across the United States. These spies were tasked with gathering and transmitting information that could be used by Germany in the event of war, as well as carrying out acts of sabotage. Members of the ring held jobs that allowed them to collect valuable intelligence, such as working in restaurants, airlines, and as delivery personnel.
The operation to dismantle the Duquesne Spy Ring was a significant achievement for the FBI and the Allied war effort. By December 1941, just days after the attack on Pearl Harbor, all members of the spy ring had been convicted or pled guilty, receiving sentences totaling over 300 years in prison. Sebold’s bravery and dedication were instrumental in this achievement, showcasing the critical role of intelligence and counterintelligence in wartime.
Later Life
After the war, Sebold lived a relatively quiet life, passing away on February 16, 1970, in Napa, California. His contributions to the Allied victory in World War II were not widely known during his lifetime, but his legacy as a courageous double agent endures. The story of William Sebold highlights the power of loyalty, bravery, and the impact one individual can have on the course of history.
Resource
Federal Bureau of Investigation
FBI.gov