A neat group of material from female codebreakers during World War II, who worked behind the scenes to break ever-changing and increasingly complex codes used by Axis powers, enabling the Allies to sink enemy supply ships, shoot down Isoroku Yamamoto, and orchestrate the invasion of Normandy. Includes: relics from the uniform of WAVES (Women Accepted for Volunteer Emergency Service) codebreaker Arnette Graham, Specialist Q, 2nd Class: five navy blue Army buttons and a patch with an anchor, taken from her uniform. WITH: two war-date T.L.S.s to LESTER HILL (1891-1961) American mathematician and developer of the ‘Hill Cypher’. During WWII the US military made extensive use of his codes. After the war he was drafted in to teach spies at the ‘American University of Biarritz’. The letters, 1p. 4to. each on ‘Bureau of Naval Personnel’ letterhead, Apr. 24 and Oct. 2, 1944 respectively, thank Hill for his support for WAVES. WITH: a printed war-date roster of 1944 WAC detachment Signal Corps for interception and cryptanalysis stationed at Vint Hills, with C.O. Ethel R. Sears, 6pp. 8vo., [n.p., n.d.], and a reverse Photostat of an honorable discharge of codebreaker Betty J. White. Three pieces, very good.