Mary Louise Prather

Mary Louise Prather (1913 – 23 December 1996) was an American spy and one of the pioneering women within the field of cryptography. Most of her work in the field of cryptography was completed during World War II and early in the Cold War era.
Prather joined the Signal Intelligence Service (SIS) as a civilian stenographer in 1938, an entry-level position, and worked a variety of jobs that included the many machines of the office. Eventually, in 1940, she achieved the position of Chief of the Stenographic section. Prather came in at her entry-level position and worked her way up to higher positions by learning the processes of different atypical office machines used for decoding. These were important in sorting of coded enemy messages for translation.