CIC Detachment Ensures Success of the Manhattan Project
Lori S. Tagg, USAICoE Command Historian
The United States program to develop the atomic bomb, codenamed the Manhattan Project, began in August 1942. From the beginning, the need for security was paramount. The project had to be protected from sabotage and espionage and, equally important, the fact that the US was working on such a program had to be kept under wraps at all cost. Early on, a Protective Security Section (PSS) handled personnel and information security, facility protection, and security education.
By February 1943, a more comprehensive counterintelligence program was warranted and Counter Intelligence Corps (CIC) agents Capt. Horace K. Calvert and Capt. Robert J. McLeod were assigned to the Manhattan Engineer District (MED) to organize the Intelligence Section. More CIC personnel followed, with agents stationed at Oak Ridge, Tennessee; Chicago; St. Louis; Site Y (Los Alamos, New Mexico); and Berkeley, California. By August 1943, when the project transferred to the Corps of Engineers, the Intelligence Section merged with the PSS and established its headquarters at Oak Ridge. At this time, the Section assumed responsibility for every aspect of security within the MED. Four months later, on December 18, 1943, a special CIC Detachment, commanded by Lt. Col. William B. Parsons, was organized, and Lt. Col. John Lansdale became the chief of intelligence and security for the entire Manhattan Project.
In the early 1940s, Lansdale, a graduate of the Virginia Military Institute (VMI) and a US Army Reserve officer, was a successful trial lawyer in Cleveland, Ohio. He had turned down several calls for active duty before finally taking the advice of one of his VMI classmates to accept special duty within the War Department’s Military Intelligence Division (MID). Lansdale initially worked in the Investigation Branch, Counter Intelligence Group, reviewing investigative reports of prospective War Department employees. He eventually became chief of both the Investigation and Review branches of MID. Another one of his duties was to act as liaison between the PSS and the Assistant Chief of Staff, Intelligence. When the Manhattan Project transferred to the Corps of Engineers and the CIC Detachment activated, Lansdale had the background and connections to move effortlessly into the position as head of intelligence and security. Due to the criticality of his mission, Lansdale quickly became special assistant to Gen. Leslie Groves, the chief of the MED.
The CIC Detachment was initially comprised of 25 officers and 137 enlisted agents, each one hand-picked by Captains Calvert and McLeod. Over the next year, the Detachment grew to 148 officers and 161 enlisted agents. This included non-CIC military personnel with specific technical abilities critical to the security of the program. Detachment Headquarters was centralized at Oak Ridge, but personnel were placed on detached service in 11 branch offices around the nation. At times, these agents were so highly classified that they were referred to by code symbols and only the Finance Officer computing the pay of the agent knew his exact location.
Lansdale assumed full responsibility for all intelligence and security matters affecting the MED. In addition to preventing unintentional disclosure of information and infiltration by enemy agents, Lansdale’s responsibilities included preventing fires and explosions, monitoring courier duties, protecting classified shipments, educating personnel about the importance of security measures, obtaining newspaper cooperation, and conducting 400,000 background investigations of potential personnel. His agents acted as bodyguards for the project’s top scientists and went undercover to monitor local rumors about the various installations involved in the bomb development. Lansdale also planned and executed the security measures for the 509th Composite Group, the special Army Air Forces’ organization formed to deliver the bombs. Additionally, he was deeply involved in the Alsos Mission, an overseas task force that seized the technology and scientists involved in German atomic research.
The dropping of the atomic bomb on Hiroshima and Nagasaki, Japan brought about the end of World War II and saved the lives of thousands of US and Allied troops who would have died in an invasion of Japan. The procedures put in place by Lansdale and his CIC Detachment led to the successful protection of the atomic bomb program, later called the “War’s Best Kept Secret.”
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