1946: Elizebeth Friedman departs the U.S. Coast Guard.
Excerpt from article by Sally J. Ling - Florida's History Detective about Famous Women of Prohibition - see the original article via the link at the bottom of the page.
In the early days of the war on liquor, the Coast Guard located smuggling vessels by cruising until they were sighted. But things quickly changed when the syndicates entered the picture bringing with them money to install larger engines and radio communication.
In 1924, the Coast Guard set up shore radio stations along the east coast of the U.S. from Nahant, Massachusetts to Fort Lauderdale, Florida, to better communicate with ships at sea. To counter this, more rum ships became radio-equipped. This resulted in the necessary establishment of clandestine radio stations on shore by the rummies. Both organizations communicated to their respective organizations by code.
Lt. Frank M. Meals, a telegraph operator and radioman, was given the task of preparing a suitable code for use strictly by the Coast Guard. Teamed up with Robert T. Brown and the Army’s Chief Cryptanalyst, Maj. William F. Friedman and his wife, Elizebeth, they produced the Coast Guard’s first official code book. William Friedman, the leading cryptologist of his time, became known as the father of modern Army cryptology. Elizebeth went on to establish quite a reputation in her own right.
Elizebeth’s first paid position was at Riverbank, the only facility in the U.S. seriously capable of solving enciphered messages. In 1923, the U.S. Navy employed her as a cryptanalyst where she led the cryptanalytic effort against international smuggling and drug-running radio and encoded messages, which the runners began to use extensively to conduct their operations.
While working for the Coast Guard during the Prohibition era, she decoded over 12,000 rum-runners’ messages. In 1933 her efforts resulted in convictions against thirty-five bootlegging ringleaders found to have violated the Volstead Act. These ringleaders were later linked directly to suspected vessels as a result of the information arising out of her analysis.