Female code breakers: The hidden figures of the greatest generation

(CNN) — Do you like crossword puzzles and are you engaged to be married?

Those were the questions asked of many college-age American women by their professors, college presidents, or military officers to assess their suitability to do secret work breaking German and Japanese codes during the Second World War.

From students at the Seven Sisters colleges in the Northeast to schoolteachers from across the South, some 10,000 women answered the call and became the backbone of America’s intelligence infrastructure. Their efforts saved lives and shortened the war. Code breaking was pivotal to the Allied defeat of Japan at sea and on the Pacific Islands, as well as to neutralizing the threat posed in the Atlantic by Nazi submarines.

Unlike the fits of genius dramatized in the films “Enigma” or “The Imitation Game,” code breaking was actually a marathon of tedium, an activity defined by comparing and recognizing patterns. In this, women’s abilities were thought to be superior to men’s. Though they went about recruiting women quite differently, both the Army and the Navy saw in American women an untapped resource for improving America’s odds for winning the war.

In her new book “Code Girls: The Untold Story of the American Women Code Breakers of World War II,” journalist Liza Mundy tells the stories of many of these women who, because they were sworn to secrecy about the nature of their work, have been all but forgotten. Just because these women agreed to be invisible to the enemy, however, doesn’t mean they need to be invisible to history.