by Lori S. Stewart, USAICoE Command Historian
8 SEPTEMBER 1931
On 8 September 1931, 1st Lt. Mark Rhoads became the first student in the Signal Intelligence School. His twenty-one-month intensive work-study program formed the basis for an expanded school three years later. The school was meant to provide, in the event of war, a sufficient pool of military officers knowledgeable in all aspects of cryptology, to augment the civilian staff.
In early 1930, the Army consolidated both code-breaking and code-making activities under the Signal Corps’ newly formed Signal Intelligence Service (SIS) in Washington, D.C. Projecting a future need for adequately trained cryptographic officers, Director William Friedman first developed correspondence courses for reserve officers. He believed, however, part-time students could not absorb the complex material well enough to become the proficient cryptographers the Army would need in wartime. Furthermore, he lamented the lack of any “civilian or military institution in this country at which special courses are conducted in compilation, application, handling, or solution of military codes and ciphers.”
Consequently, the SIS director lobbied for a Signal Intelligence School within his organization. This would not be a standard school with a classroom of students receiving instruction from a pool of professors. Instead, it would be a one-year intensive internship for a single student whose sole duty would be to learn from the Army’s noted civilian cryptographers in the SIS: Friedman, Soloman Kullback, Abraham Sinkov, Frank Rowlett, and William Hurt. [See "This Week in MI History" 1 April 1930] Friedman received approval in October 1930, and the first student carefully chosen for this privileged opportunity was Lieutenant Rhoads, the first Regular Army officer assigned to the SIS.
Rhoads did not start his military career in the shadowy world of codes and ciphers. A 1918 graduate of the U.S. Military Academy, the Pennsylvanian had been commissioned in the Cavalry. By 1923, however, he had moved into the field of communications, graduating from the Signal Corps’ Communications Officers Course at Fort Monmouth, New Jersey, and then completing a post-graduate degree in communications engineering at Yale University. In 1927, he transferred to the Signal Corps and became a signal instructor in Indiana and Kentucky.
The 34-year-old Rhoads started his SIS detail on 8 September 1931. The course was to give him a solid foundation in the compilation and solution of codes and ciphers, operation of radio intercept and radio goniometric organizations, and creation and detection of secret inks. Before long, Friedman realized he had underestimated the time needed to train Rhoads properly. Seven months into the course, Rhoads, an excellent student, had only superficially studied various types of cipher systems; his training in code systems, radio intercept, and secret inks had not even begun. Friedman estimated Rhoads would need at least another eleven months to adequately learn those subjects.
In April 1932, Friedman successfully lobbied to extend the course to two years, with a one-month leave of absence at the mid-point to give the student some mental relief from the complex material. Also, as Rhoads entered his second year, another student, 1st Lt. W. Preston Corderman, started his first year, thus beginning a regular cycle of students that became a formalized Signal Intelligence School in July 1934.
Rhoads completed his course in May 1933. In addition to working on cipher problems, code compilation, and secret inks, in his last eight months, he spent three hours a week studying the Japanese language under the tutelage of Mr. Hurt and two hours per week studying Russian at the Department of Agriculture. After helping develop the new school curriculum, now Capt. Rhoads took command of the Provisional Radio Intelligence Detachment, 51st Signal Battalion at Fort Monmouth, the Army’s first operational radio intelligence unit since 1918. While deployed with the detachment to the Philippines in 1935 to set up an intercept station, Rhoads contracted pulmonary tuberculosis, which forced him into involuntary retirement in March 1937.
Despite several attempts to return to active military duty, Rhoads was hired at the now renamed Signal Security Agency as a civilian in 1943. He spent six years as assistant director of Communications Research under his former mentor, William Friedman, before transferring in July 1949 to the Armed Forces Security Agency as assistant to the chief of the Technical Division, again Friedman. In early 1952, Rhoads was again forced into retirement by the disease he had contracted seventeen years earlier.