America’s code girls

Female codebreakers and their wartime service

Created date

September 13th, 2018
Women code breakers worked tireless for both the U.S. Army and Navy. This black and white photo shows several of the women hard at work.

Women code breakers worked tireless for both the U.S. Army and Navy. This black and white photo shows several of the women hard at work.

When it comes to World War II code breaking, few names are bigger than Bletchley Park. Located in the south of England, this legendary facility housed Great Britain’s Government Code and Cypher School and, more importantly, the teams of young female code breakers who cracked the German Enigma cipher.

Their efforts helped to suppress the U-Boat peril that had crippled Allied supply lines on the North Atlantic and, by some estimates, shaved two years off the war in Europe. Today, Bletchley is a national historic site, well preserved, open to the public, and meant to perpetuate the code breakers’ legacy.

Far less known is that the United States was likewise in this life-or-death race and in possession of its own teams of code breakers—again, mostly women. They are the subject of the best-selling book Code Girls: The Untold Story of the American Women Code Breakers of World War II (Hachette, 2017).

Around 1940, amidst growing tensions with Japan, the U.S. Navy and Army began recruiting and training code breakers to gather critical military and political intelligence on the tenuous relationship with the island nation’s diplomats.

By 1942, when the war was in full swing, the military was hiring women from a number of America’s elite female colleges. The Navy pulled candidates from the student bodies of Radcliffe, Wellesley, Vassar, and Goucher; the Army harvested its code breakers from teaching colleges across the country.

In total, roughly 11,000 women served as code breakers during World War II. But how has this story managed to slip under the radar for so many years while Bletchley remains common knowledge?

Code Girls author Liza Mundy cites several reasons.

The first, and perhaps most obvious explanation, is that Bletchley Park has long been a place where tourists could visit and learn about the importance of code breaking in warfare and the contribution of those who made it possible.

The matter of secrecy was another factor.

Top-secret work

“When these women came to Washington, their superiors made it clear that this was strictly classified work,” says Mundy. “This was very serious, and to talk about it would have been treason.”

After Japan’s surrender, the government simply thanked them for their service. And so, dutifully silent about their wartime experiences, they returned home, got married, and quietly went on with their lives, which is difficult to fathom given the magnitude of their accomplishments.

In September 1940, for instance, Army code breaker Genevieve Grotjan had made a key breakthrough that enabled Allies to eavesdrop on Japanese communications for the rest of the war. The intelligence we were getting was from Japanese diplomats stationed in Europe, specifically, Vichy, France; Italy; and Germany.

“Japan’s diplomats were routinely talking to Hitler and Mussolini,” says Mundy. “They were also reading the papers, and they were reporting news and other information back to Japan all the time.”

The Allies read every message thanks to the women who had broken the code.

One such piece of intelligence arrived after Japanese representatives toured Hitler’s Atlantic Wall. Here the Germans had already built fortifications in anticipation of an Allied landing.

“When the diplomats reported back to Tokyo,” says Mundy, “they noted where the coast was well fortified and where it wasn’t. As a result, we knew Calais was better fortified than Normandy.”

An author’s determination

In the code breakers’ spirit, Mundy relied on persistence to get her job done. In the course of her research, she used genealogical databases to determine code breakers’ married names.

“From there, I had to make 20 or 30 cold calls each, and most of the numbers were either dead or disconnected,” she remembers. “Every once in a while, someone would pick up the phone, like Ruth Mirsky and Dorothy Ramale, both of whom are in my book; they were delighted to talk with me, which is great.”

Others, however, were reluctant. The book’s central character, Dot Braden, still feared that she might violate her oath.

“I had to work pretty hard to convince her that the men had started talking a long time ago,” recalls Mundy. “They had been released from their oath of secrecy.”

Fortunately, she persuaded Dot and many of her colleagues. They helped win World War II and made for a great book in the process.