Code Girls: The Untold Story of the American Women Code Breakers of World War II

by Liza Mundy

Nearly half of the men who died were on the Arizona, among them twenty-three pairs of brothers.

After the war, the U.S. Army and Navy code-breaking operations merged to become what is now the National Security Agency. It was women who helped found the field of clandestine eavesdropping—much bigger and more controversial now than it was then—and it was women in many cases who shaped the early culture of the NSA.

The Federal Communications Commission and the Federal Bureau of Investigation and the new Office of Strategic Services (OSS)—forerunner of the CIA—all vied for a piece of the code-breaking action.

That women were considered better suited for code-breaking work—as the letter that Rear Admiral Noyes sent to Ada Comstock suggested—wasn’t a compliment. To the contrary. What this meant was that women were considered better equipped for boring work that required close attention to detail rather than leaps of genius.

In 1942, only about 4 percent of American women had completed four years of college.

One electrical company asked for twenty female engineers from Goucher, with the added request, “Select beautiful ones for we don’t want them on our hands after the war.”

Major General Stephen Chamberlin, who served in the Pacific, announced that military intelligence, most of which came from code breaking, “saved us many thousands of lives” in the Pacific theater alone, “and shortened the war by no less than two years.”

Five days a week, eight hours a day, Dot Braden ran from classroom to classroom, teaching, lecturing, grading, marching. For her pains she was paid $900 a year, or about $5 a day.

This was another reason schoolteachers like Dot were perfect: They were almost always unmarried. In America in the 1940s, three-quarters of local school boards (like telephone companies and other employers of female labor) had enacted a “marriage bar,” which required that married women not be hired and that a teacher must resign when she did marry, in accordance with the prevailing belief that a wife’s place was at home. By definition, then, many female schoolteachers were single.

War, though, began to transform the tenor of the operation. As unlikely as the setting was, Fabyan’s estate incubated the first serious cryptanalytic efforts of the U.S military.

Switchboard operation was women’s work, and male soldiers refused to do it. French operators were not as adept as American ones, so the Signal Corps recruited U.S. switchboard operators who were bilingual in English and French and loaded them into ships bound for Europe. Known as the “Hello Girls,” these were the first American women other than nurses to be sent by the U.S. military into harm’s way.

Henry Stimson—Hoover’s new secretary of state—was shocked to learn that Yardley’s bureau was penetrating the private diplomatic missives of other countries. Stimson in 1929 shuttered the operation, cutting off State Department funding and primly explaining that gentlemen do not read one another’s mail—something European gentlemen did all the time, of course, and had been doing for hundreds of years.

Thanks to that loophole, American women were permitted to enlist in the naval reserves during World War I, and the designation “Yeoman (F)” was created.

Japan had defeated Russia in 1905 and it clearly wanted to build a Pacific fleet to rival or surpass America’s; and, lacking the natural resources such as oil, iron, and rubber it needed to become a dominant world power, it seemed bound to go looking for those resources elsewhere in the Pacific region, threatening U.S. territories including Guam and the Philippines.

Coordinator of Information—the nation’s new spy service—soon to be renamed the Office of Strategic Services.

One of the best was called Enigma. Envisioned as a tool for bankers, the Enigma, invented by a German engineer and marketed by a German company in the 1920s, had been adapted for military use by the Nazis.

Since “the” is often omitted from a telegraphed message, the statistical behavior of E changes slightly in a telegram.

intercepts. The intent was that the very existence of Arlington Hall not be mentioned outside its gates, but in time-honored government fashion, a press release was accidentally issued.

In Cincinnati’s Union Terminal, he told them, predatory women lurked. It’s possible to imagine the audience at this point uneasily shifting in their chairs, as Taft blamed their gender for much of the nation’s moral ills and social dislocations.

At the end of this soliloquy on laundry, grocery shopping, troublesome children, pox, prostitution, and other developments caused by wartime changes in their own behavior, the female code breakers of Arlington Hall were invited to rise and sing the first verse of “The Star-Spangled Banner.”

It was true that the first six months of 1942 were a dark and disheartened time for the United States, especially for the U.S. Navy.

At the outset of the war, the Japanese Navy controlled one-quarter of the Pacific Ocean and had not lost a naval battle in more than fifty years.

Just hours after Pearl Harbor, the Japanese launched air attacks on the Philippines. They captured Guam, in the Marianas, two days later, and took Wake Island before Christmas. Meanwhile the Japanese Army was stabbing westward and southward, capturing British and Dutch colonial holdings.

The Outer Banks of North Carolina became known as “torpedo junction” because of the number of ships destroyed there.

Making things worse was the fact that the Germans were reading the cipher the Allies used to direct their convoys, something the Americans suspected but the British were slow to admit.

The British built sixty “bombe” machines, which, beginning in 1941, were run by some two thousand members of the Women’s Royal Naval Service, or Wrens.

Churchill called his Bletchley code breakers the “geese that laid the golden eggs, and never cackled.”

In February 1942, however, the hypercautious German Navy added a fourth rotor to the naval U-boat Enigma machines, increasing the possible combinations by a factor of twenty-six. The Allies called this new four-rotor cipher “Shark,” and initially it proved impenetrable. The Allies lost the ability to read U-boats. The whole system went dark. This crushing turn of events occurred just months after the United States entered the war, and it began an eight-month period of death and destruction and helplessness, a time when ship after ship went down and it felt very much as though the war could swing the wrong way.

The four-day Battle of Midway was an unparalleled American victory. One of the most storied naval battles in world history, it marked the end of Japan’s expansion in the Pacific and a major turning point in the war.

The Midway victory also set in motion one of history’s great bureaucratic backstabbings. Joseph Wenger and John Redman, two of the top intelligence officers in Washington, had believed the attack would happen a week later than it did. Joe Rochefort and the team in Pearl Harbor had gotten the date right. To cover their mistake, the Washington bigwigs (who feared Rochefort was building a unit to compete with theirs) let it be known that they were the ones who had pinpointed the correct date, and Pearl Harbor had gotten it wrong. This shocking lie found its way all the way up to Ernest King, commander in chief of the U.S. Fleet. Redman and Wenger continued to conspire against Rochefort, who eventually was relieved of his command and put in charge of a dry dock.

President Roosevelt signed the WAAC bill into law in May 1942, a mixed victory in that women were allowed into the Army on an “auxiliary,” or inferior, basis. WAACs were paid less than men and did not hold the same ranks or receive the benefits. Some of this disparity would be rectified when “auxiliary” was dropped in 1943 and the WAACs became WACs, but women were by no means equal.

The Army women were barred from serving as combatants but did fill important ancillary posts. They served as drivers, accountants, draftsmen, cooks, occupational therapists, encoders.

Jaenn Coz, whose mother had been a flapper, would sometimes put on civilian clothes, surreptitiously, and go to the “black part of town,” as she put it, to hear Eartha Kitt. Frank Sinatra would sing at Club 400, where she went on Fridays. You could buy a pitcher of beer for a few cents. You could get good fish down at the wharf. She also learned to play bridge and to gamble.

The escapade found its way into the Washington Post, which noted the breach in a gossip item headlined SECRET WAR DOCUMENTS PROVE ABOUT AS HARD TO GET AS A COLD.

At the end of the war, a U.S. naval report found that “more than two-thirds of the entire Japanese merchant marine and numerous warships, including some of every category, were sunk.

He pointed out that code breaking was responsible for at least 50 percent of all marus sunk by subs.

Beginning in 1943, starvation became the common lot of the Japanese soldier. Officials later estimated that two-thirds of Japanese military deaths were the result of starvation or lack of medical supplies.

Neither Jimmie Lee nor Bob had ever heard of trick-or-treating, which was not something people did in Oklahoma, so their first Halloween, in October 1943, they felt like kids.

“Since 13 September 1943, every message in that cipher has been read and since 1 April 1944 the average delay in ‘breaking’ the daily key has been about twelve hours. This means that for the last half of each day, we can read messages to and from Atlantic and Indian Ocean U-boats simultaneously with the enemy. In fact, during these hours the translation of every message sent by a U-boat is at hand about twenty minutes after it was originally transmitted. At present, approximately 15 percent of these keys are solved by the British and the remainder by OP-20-G.”

The U-boats had to report whether they sank an Allied ship or whether any U-boats had been sunk, and the women used these Enigma messages—along with files on individual U-boats and their commanders—to track, with pins, every U-boat and convoy whose location was known.

At another desk, several other Goucher women, including Jacqueline Jenkins (later the mother of Bill Nye, aka Bill Nye the Science Guy), tracked “neutral shipping” based on daily position reports.

After the carnage of 1942 and early 1943, the Allies had seen a stunning turnaround in the Atlantic. By September 1943, most U-boats had been swept from the Atlantic waters.

All of this was run through the embassy’s Purple machine in Berlin, transmitted to Tokyo, plucked out of the air by WACs working at the Vint Hill intercept facility, deciphered by the Purple unit at Arlington Hall—mostly young civilian women sitting side by side at a table in Building A—and rendered into English by linguists in the translating division.

The women operated the SIGABA machines, which were America’s version of the Enigma. The SIGABA was initially conceived by William Friedman to encipher U.S. Army traffic, its design then improved by Frank Rowlett; the reason it was never as famous as the German Enigma was because unlike the German Enigma, it was never cracked.

The Allies had won the Battle of the Atlantic—and the European war. Admiral Dönitz—the new head of state in Germany—ordered his U-boats to stand down.