July 16,  1943, the first Women’s Army Corps (WAC) personnel arrived at Arlington Hall Station to serve as cryptanalysts, traffic analysts, and clerk-typists.

Although small detachments of WACs served at the Signal Security Agency (SSA) two “listening posts” at Vint Hill Farms, Virginia, and Two Rock Ranch, California, primarily as radio intercept operators, the largest the largest of the SSA’s WAC contingent served at Arlington Hall Station as cryptanalysts, traffic analysts, and clerk-typists.  WACs at the two “listening posts” spent their days copying Morse transmissions and transcribing intercepts from both the German and Japanese armies. Intercepts of interest were sent to Arlington Hall Station where WACs processed and evaluated nearly 4,000 intercepted messages daily.

At the end of the war, the WAC detachments were disbanded, although some women were reassigned with US occupational forces overseas. The Army’s signal intelligence (SIGINT) field closed to women until 1971, when the SSA’s successor, the Army Security Agency, was granted authority to enlist women.

Source: cryptologicfoundation.org