The horrors and heroes of World Wars I and II have long been commemorated on the page and screen, yet comparatively little is known of the individuals who did more than keep calm and carry on off the battlefield. From switchboard operators to covert codebreakers, unsung workers at home and overseas played a pivotal role in securing Allied victory. We spoke with the authors of three new books for young readers that shine the light on some of the lesser-known stories of civilian ingenuity and bravery—women and teens who contributed to the war efforts in their own invaluable way.

Hello from the Other Side

Monica Hesse was deep in the writing trenches with another YA novel set in 1918 when the concept for The Brightwood Code (Little, Brown, May 14) first struck her. “Whenever I’m struggling with a piece of historical fiction, the answer is usually that I don’t understand the time period fully enough. I was talking about this with my husband, and he started doing research, too. He came to me and asked, ‘Well, have you thought about the Hello Girls?’ I’d never even heard of them; it was like a whole new chapter had been unlocked. It started from there.”

The more she learned about these young women, who were hired by the U.S. Army as bilingual telephone operators and stationed in France to improve wartime communication, she wondered, “How have I been so immersed in this time period for so long, and there’s this aspect of history that I’ve never heard about? I just felt like, if this was something that I wasn’t aware of, chances were good that a lot of people wouldn’t have heard of it either.”

Hesse noted, “What’s doubly interesting is that even though these women were being recruited and trained by the government and were being sent to the front lines, they were never considered military. They were considered civilian contractors, which meant that they didn’t get military benefits. They came home, and then a 50-year fight ensued for them to try to get recognition for the work that they had done. And the recognition did eventually come, but it was generations later.” In addition to writing historical YA, Hesse is a columnist at the Washington Post, reporting on feminist issues and gender discrimination, and she sensed this was fertile ground for a novel.

The Brightwood Code alternates between flashbacks of teen Edda in WWI France, where she is one of 200 women serving as a Hello Girl with the American Expeditionary Forces; and after the war, in D.C., where she works as an American Bell Telephone operator. Late one night during her shift, she receives a mysterious call that plunges her back into intrigue connected with her wartime activities. Hesse said she takes “a three-dimensional, multi-sensory” approach to her historical investigations. “Equally important is the research about the life that people would have been living at that time. I like to read books, visit museums, and try to get my hands on fashion or lifestyle magazines from the era, so that I know what my character would have been wearing or eating or reading. Even though a lot of that might not make it into the book,” she said, “I find it necessary to think about the culture that my main characters are absorbing.”

The everyday details she uncovered about the life of a telephone operator were especially illuminating. “They gave a window into the struggles that women made at the time to be respected in the workplace, and how that is similar or different to the things that women continue to think about today,” Hesse said. She hit on a treasure trove of primary sources, in the form of archival footage. “AT&T has a collection of YouTube videos that go back to the beginning of the company’s history, and you can watch the training videos for operators in the 1910s and 1920s!”

Placing the job in the context of women’s restricted professional lives during that period, she said, “At the time, the opportunities for women’s work were extremely limited. The respectable professions basically would have been librarian, teacher, or nurse. Telephone operator wouldn’t have been a scandalous profession, but it was not considered a professional class. It wasn’t something that parents would have been necessarily excited about their daughters doing. And so there was this big push to make it look respectable,” which was reflected in the training videos of the day.

Hesse found that the work culture was “very regimented. The girls had to meet height and weight requirements because they sat in very small booths. You weren’t allowed to have romantic relationships, you weren’t allowed to date, and you weren’t allowed to socialize in between your calls, because they really wanted the Bell Girls to be the model of decorum. It was kind of a pressure cooker in that way.” That level of detail “was really helpful to me in thinking about this time where we were trying to figure out what women were and weren’t allowed to do.”

Looking at the impact of these young women on future war efforts, she said, “The Hello Girls really were the foremothers for women’s participation in the war. They were the first example of a codified program in which the country said, we need women to fight and win this war. It was a test case that the suffragettes and feminists were behind. They knew that if the Hello Girls could be successful, it could leave an open door for the rest of the women in the country to prove their worth. It was a high-stakes operation.” And it worked. “The things that codebreakers were doing by the time of Bletchley in World War II—none of that would have been possible if the Hello Girls hadn’t proved how valuable they could be a generation prior.”

Spies Among Us

A trip to the International Spy Museum in Washington, D.C., sparked author Marissa Moss’s interest in the life and work of cryptanalyst Elizebeth Smith Friedman (1892–1980). “I knew about the Enigma machine and Alan Turing,” she said, “but I didn’t know about what Americans were doing [at that time]. And all that stuff was recently declassified, so it was exciting to know that I could get a hold of information that was previously not available,” including interviews, radio programs, Friedman’s own writing, and others’ research. “It was just too juicy not to do.”

The author of books on Civil War hero Sarah Emma Edmonds, 20th-century Jewish physicist Lise Meitner, and many other female historical figures, Moss said, “I’ve been writing about women who should be better known for decades now. And I feel like the timing has always been right for that.”

As in her previous book, The Woman Who Split the Atom, Moss integrates original drawings throughout Spying on Spies: How Elizebeth Smith Friedman Broke the Nazis’ Secret Codes (Abrams, out now), which is aimed at middle graders. “I thought that using graphic novel pages in front of each chapter would make the subject matter more accessible,” she said. “You see the time period, and it takes away the distancing that often happens [with books set] in the past.”

Moss has also written picture books and said she’s partial to visual storytelling. “I like to go back and forth between words and pictures, because that’s how my brain works. There’s a lot of information you get through images that you don’t get through words.” She found that the hybrid format of prose and illustration lent itself to the topic of codebreaking. “I feel like it really gives you a fuller story. And codes are visual; Friedman was looking at visual patterns.”

Moss’s research led her to several unexpected discoveries. “I was shocked that Elizebeth and her husband [William Friedman] were the only codebreakers during the whole first half of World War I. There was no CIA. There was no NSA or spy apparatus. And this young couple who had no training were breaking all the codes—I found that mind-blowing!” Especially impressive, Moss said, was the fact that “Elizebeth was cracking codes in Chinese and Portuguese—languages she couldn’t read—because she could recognize patterns. She had a Chinese translator come in and work on the code, but her guesses for the words were all 100% accurate.”

During World War II, even though Friedman didn’t have access to the extensive codebreaking machinery and staff of Bletchley Park, Moss said, “she broke the Enigma machine [the cipher device used by Nazi Germany] at the same time as Turing, which I find very satisfying and validating. Because, of course, we hear about Turing, and he deserves it—not to take away from that. But she had even more prejudice against her and a steeper hill to climb to get to where she was, because women couldn’t be in the military. All the other codebreakers were men.”

Thankfully, Friedman found a supportive partner in her husband. “She had this partnership with William where they were both working on spy stuff, and they couldn’t even tell each other what they were working on. They slept in separate rooms, so they wouldn’t let something slip while they were sleeping—just amazing, amusing details like that.”

Moss hopes that readers of her book “see that you can do things that people tell you you can’t. Elizebeth’s father told her she couldn’t go to college. Everybody told her she couldn’t get a job. But she just soldiered on. She was really determined to do something, and she had an incredible life.”

Inside Station X

Like Moss, Candace Fleming found inspiration for her nonfiction book, The Enigma Girls: How Ten Teenagers Broke Ciphers, Kept Secrets, and Helped Win World War II (Scholastic Focus, out now), during a field trip: to Bletchley Park in Buckinghamshire, the site of the famous WWII codebreaking factory. One of the displays on view at the estate—once the top-secret “Station X” and now open to the public—shows the demographics of the nearly 9,000 individuals who worked there. “When I looked at it,” Fleming said, “I realized that most of them were women. And then when I looked closer, I saw that most of those women were between the ages of 14 and 19.” She was eager to learn more. “I discovered lots of stories left behind by these women—most of them now deceased—about their time in Bletchley Park: how they arrived, how they lived, how they had to leave their families and go to a place that no one could talk about. I just thought it was an astonishing story, all the way around.”

While many are familiar with the work of Alan Turing and Tommy Flowers, “all these experts, these geniuses,” she said, “we never talk about those people who went in and did the work every single day. And those girls did the slogging grinding work. The government needed their energy and their youth to do what they knew were going to be repetitive, dull jobs. I think too often we don’t call those people heroic.” Nevertheless, their contributions were crucial. According to historians, the team at Bletchley Park shortened the war by three years.

Narrowing her field of inquiry to 10 women was a challenging undertaking for Fleming. “I had a span of 1939 to 1945—from Bletchley’s developmental stage, towards the very end when they had Colossus,” the world’s first programmable computer, built by Flowers to decipher encrypted German messages. Fleming explained, “I wanted to bring in different young women who came to Bletchley at different times, so that my readers could see the change. And I also wanted girls from different parts of society,” including Sarah Norton, the daughter of an English lord, as well as girls like Gwen Watkins, who came from ordinary homes. Fleming also selected her subjects to reflect the diverse roles within the operations. “I wanted to show readers all the different jobs that were being done by young women, not just running those massive Bombe machines [used for codebreaking] like Diane Payne, but also the indexing, the translating like Sarah Norton, and using the Typex [cypher machines].”

It’s clear the author has developed a deep respect and admiration for these intrepid young women, referring to them at several moments in the interview as “my girls.” Aside from a select few, such as 18-year-old Mavis Fleming, who worked closely with Dilly Knox, a Greek scholar and papyrologist, Fleming said, “most of my girls were not cipher breakers. The rest of them didn’t even hear the word ‘Enigma’ during the time they were there.” Therein lies the heart of the story’s appeal for Fleming. “I think that’s probably one of the most fascinating parts. They were so secretive; they weren’t allowed to talk to anybody at work about what they were doing. Even if you had two women sitting next to each other on the Typex machine.”

The bitter irony is that, when the men returned from war, the women were cast out from this dynamic world of codebreakers to take up their role in the “traditional sphere” as homemakers. “These were women who were actually in some cases using their skills and degrees. There was one mathematician from Oxford, which was rare in and of itself, and she had an unbelievably difficult technical job that required a lot of patience and intelligence—and she loved every minute of it. But then, of course, she was unable to get work as a mathematician.” Due to the Official Secrets Act, they were forbidden to disclose the nature of their work at Bletchley Park to friends or family for decades afterward.

Their stories are also coming to light in the forthcoming middle-grade historical adventure The Bletchley Riddle, cowritten by Ruta Sepetys and Steve Sheinkin (Viking, Oct. 8) and in the recent picture book Codebreaker Charlotte by Cedar Wang (Clavis, Apr.). Why the seemingly sudden confluence of books on these topics? Fleming said, “Maybe it’s because we’re so interested in women in STEM. You worry about those women being forgotten, right? We will probably remember Elizebeth Smith Friedman, but we might not remember Diana Payne,” and others featured in The Enigma Girls. “So I hope when readers get to the end they will have had a really great read about some really great women.”

On the broader relevance and resonance of books set in previous eras, Hesse said, “I think historical fiction is a safe space to discuss complicated and thorny issues, because it allows young readers to think about and wrestle with big things like gender discrimination or the atrocities of war from a step of remove. That kind of thinking helps you prepare yourself for how to engage with the world.” She added, “I hope that readers think about this complex, messy world that we live in, and the role of everyone in it, and what that means for where we want to go in the future.”

The Brightwood Code by Monica Hesse. Little, Brown, $18.99, May 14 ISBN 978-0-316-04565-0

The Enigma Girls: How Ten Teenagers Broke Ciphers, Kept Secrets, and Helped Win World War II by Candace Fleming. Scholastic Focus, $19.99, Mar. ISBN 978-1-338-74957-1

Spying on Spies: How Elizebeth Smith Friedman Broke the Nazis’ Secret Codes by Marissa Moss. Abrams, $19.99, Feb. ISBN 978-1-4197-6731-9