The American Black Chamber

During the 1920s Herbert O. Yardley was chief of the first peacetime cryptanalytic organization in the United States, the ancestor of today's National Security Agency. Funded by the U.S. Army and the Department of State and working out of New York, his small and highly secret unit succeeded in breaking the diplomatic codes of several nations, including Japan. The decrypts played a critical role in U.S. diplomacy. Despite its extraordinary successes, the Black Chamber, as it came to known, w...