Code Girls

Introduction to the Female Code Breakers

The Pearl Harbor attack on December 7, 1941, caught the United States completely by surprise. The military quickly realized it lacked the necessary intelligence to fight a massive two-ocean war. Because building a traditional spy network would take years, the government decided that breaking enemy communications was the fastest solution. This urgent need led to a massive, secret effort to recruit thousands of educated women.

The Navy began its search at elite women's colleges like Wellesley and Smith. Professors invited top students to private interviews, specifically looking for women with math skills and no immediate marriage plans. These recruits took secret correspondence courses in cryptanalysis, which is the study of codes and ciphers. They learned to analyze letter frequencies and scramble messages while keeping their training completely hidden from their families.

The Army conducted its own search at teaching colleges in the South and Midwest. They sought women with backgrounds in math and foreign languages who wanted to serve their country. Many recruits saw this as a chance to escape low-paying teaching jobs and support brothers fighting overseas. They moved to Washington with no clear idea of their actual duties, only knowing their country needed them.

These recruitment efforts created a massive secret army of female code breakers. More than ten thousand women moved to the capital to apply their education to the war effort. They became the backbone of an operation that allowed the Allies to read enemy conversations in real time. Their daily work provided vital data on enemy troop movements, political alliances, and shipping schedules.

The military initially believed women were only suited for tedious sorting tasks. However, code breaking proved to be a highly collaborative effort that required shared memory and teamwork rather than isolated genius. Because these women did not expect public credit in a male-dominated military, they eagerly shared observations to unlock complex systems. By the end of the war, women made up the vast majority of the domestic intelligence staff.