Liz Mundy has written a well researched and documented story of the women who helped win WWII. The Navy and the Army recruited hundreds of women from universities and the teaching profession to become code breakers. Their work, particularly in breaking the Japanese codes, played a vital role in saving American lives and in winning the war. This book tells the story of a few women in particular, and gives a fascinating view of the not only their working world, but war-time life in general. I found it a tad dry in a few places, but overall very interesting. I had never heard anything about this at all, so found it quite a fascinating tale. My dad was a code breaker in the Navy during WWII, and I so wish he was still here so I could discuss this book with him. Many thanks to NetGalley and Hachette Books for the ARC. 4 stars! Excellent history!

I love reading well written history books and my interest mostly lies in politics or WWII. However, my knowledge about the Second World War has been limited to Nazism, the Holocaust and the occupation of Paris. This book covers a new aspect of the war for me – an American women’s perspective. Many men have been recognized and celebrated for the parts they played in the Allied victory and all of them were well deserved. However, what we never realize is the extent of involvement of women in wartime activities and how they have never been appropriately appreciated. This book gives a small glimpse into the lives of some such women code breakers who played a crucial part in the war.

This was a time when women wanted to get educated, even in unusual fields like math and science but didn’t have many job prospects because all the “important” jobs were required for men. This forced even highly intelligent and capable women to settle for low paying teaching jobs, sometimes in remote places with no facilities. But the war changed everything. All the healthy men were needed to fight the war from the frontlines and it was only the women who were left and they had to be engaged in intelligence activities to support the forces and gain advantage over the Axis powers. This books tells the story of how highly intelligent women graduates were picked from colleges and also school teachers who were tested and shipped to DC. They were sworn to an oath of secrecy, mostly had to learn cryptanalysis on the job and get to work immediately. They played a crucial role in the battle of Midway, the attack and killing of Japanese commander Yamamoto who was responsible for Pearl Harbor and the sinking of many enemy ships. Their code breaking skills were highly responsible for cutting off supplies to the Japanese troops in the Pacific and create a diversion that helped the Allied forces in the D-Day invasion of Normandy.

The book describes a lot of technical details about code breaking in the initial days and might be very interesting for readers of the profession. It explores the relationships that these amazing women forged with each other and in some cases maintained their whole life. But the author is also able to show us how these women were affected by the war – they were happy when they helped in the defeat of the enemies, satisfied with saving the lives of their countrymen but also devastated when their own family members sacrificed their lives. Their aspirations, friendships, vulnerabilities are captured well in the book. At the same time, the stereotypes and misogyny they faced is also quite clearly captured.

What happened to these women after the war is worth noting and mentioned in the last chapter. Most of the women had to settle as homemakers because the jobs were for men and they couldn’t disclose their code breaking activities. Some women did manage to go back to college and become professionals in other fields. Nothing would ever be the same for them though. However, some women managed to remain in the code breaking profession. But most of them remained close to each other because only they understood.

I feel proud and privileged to read about these women. We should appreciate what they did in times when women were not considered capable of anything other than being housewives and mothers. They have made it possible for us to pursue our dreams and prove that women can be anything they want to be. I salute these amazing women for their work and it’s time they are all celebrated. And I thank the author for bringing their story to us.

Code Girls was such an interesting read! Usually I am not a huge fan of nonfiction, history books but this one drew me in. I loved reading about how these women worked hard to learn code-breaking and the differences they made in the war. Fantastic read.

CODE GIRLS is a comprehensive (432 page) look at the way that women came to the forefront of WW2 code breaking efforts. Those who love WW2 history and the early days of code (prelude to the modern computer industry) will find many interesting facts and profiles about those who served during WW2. This book is a gift to the future because the author relies on oral histories of women who served as well as countless recently-declassified documents.

The women code breakers toiled desperate, long hours without much recognition due to the fact that the work remained classified "top secret" for decades after war's end. American cryptographers in both Army (civilian corps) and Navy (WAVES and civilians) focused mainly on the Pacific/Japanese ciphers. That said, a cadre of code breakers coordinated efforts with Bletchley Park assembling an ultra-secret "Bombe" installation in Dayton, Ohio, where they toiled around the clock to crack the next-generation Enigma ciphers.

I especially liked following specific code breakthroughs and places on the map that are mentioned in this book. Deciphering Japanese codes (or failing to do so) directly affected allied victories/defeats in the Pacific. While reading CODE GIRLS, I excavated my father-in-law's log book of where he was stationed in the Pacific (as a USN photographer's mate). This gave me a deeper appreciation of the vivid historical moments that comprised WW2. Without the code breakers, the outcome would have been different.

CODE GIRLS is also a useful source for those who want to study emerging roles of women in the workplace, a topic that author/journalist Liza Mundy has researched extensively. Women in the 1930s-1940s who left traditional home life and jumped into the workplace opened doors for sisters in future generations.

An absolutely fascinating look at the work these women did during WWII. Very well researched and written.

I'm in some kind of hush, hush business. Somewhere in Wash. D.C. If I say anything I'll get hung for sure. I guess I signed my life away. But I don't mind it.
Code Girls, author Liza Mundy's historical account of the young women who worked tirelessly cracking codes to aid the American Army and Navy in World War II, opens with this quote from Jaenn Magdalene Coz, extracted from a letter to her mother, and it never lets up from there.

Mundy notes in this group biography that it's well-known how many women enthusiastically contributed to the war effort, particularly in factories, immortalized with the image of Rosie the Riveter. "Far less well-known is that more than ten thousand women traveled to Washington, D.C., to lend their minds and their hard-won educations to the war effort. The recruitment of these American women - and the fact that women were behind some of the most significant individual code-breaking triumphs of the war - was one of the best-kept secrets of the conflict. The military and strategic importance of their work was enormous.

They were recruited with various methods for a couple of stations connected to either the Army or Navy, and many ended up at D.C.'s Arlington Hall, headquarters of the Army's Signal Intelligence Service, its cryptography division. It's true that the government went to great lengths to preserve secrecy around its code-breaking endeavors, putting the participating women under gag orders for decades. Coz quoted above wasn't far off in her assumption that leaking what her work entailed would result in punishment as severe as death.

The women were told that just because they were female, that did not mean they would not be shot if they told anybody what they were doing. They were not to think their sex might spare them the full consequences for treason in wartime.
Recently, there's been a refreshing wave of books exploring and celebrating the efforts made by women, previously unrecognized or not widely known, contributing to major milestones in American history. The Girls of Atomic City is another "untold story" of women who helped win the Second World War by enriching uranium for atomic bombs. Hidden Figures highlights the African-American mathematicians at NASA who helped advance the U.S. space program, and The Radium Girls covers the women who painted clock faces with glowing radium during World War I. I've never read any of these! What kind of nonfiction reviewer who loves women's stories am I?! They're all on my list, I just hadn't cracked any yet, but Code Girls was a great entry into this fantastic, important genre.

It's fascinating from start to finish, without a single dull moment like those that too often characterize history books. Mundy covers all the bases: we learn about the women, their backgrounds, personal lives, and work (sometimes even the code breaking nitty gritty) and how it all fits into cultural and wartime contexts, as well as how their exhaustive efforts affected and were incorporated into military schematics. Then there's the development of code breaking.

One prominent woman involved, Elizebeth Friedman, was one of the few with cryptography experience prior to being recruited. She'd worked on breaking codes used to ship alcohol into America during Prohibition, when it was legal to drink but illegal to get, essentially. Mundy explains this shipping, called rum-running, was similar as a lucrative business to modern drug cartels, and Friedman was active in Coast Guard law enforcement, deciphering rumrunner messages.

Friedman had taught them during their training...that you can break a foreign cipher without understanding the language, as long as you know how the letters in that language behave. Certain letters, like S, often travel alongside certain other letters, like T...
Even this methodology, explained in evolving forms as the enemy changes tactics, is completely fascinating and never dry. The American women's work is also influenced by the work done by British and Australian cryptographers, and we get lots of details on how the Allies aided one another, like on the infamous German Enigma machine.

One male cryptanalyst, the Yale-educated Frank Raven, brought into the Navy's office of cryptanalysis work, engaged in one of the dramas that often enveloped this kind of work, where there was little squabbling or backstabbing over promotions or pay, and rather competition over who could find the correct solution the fastest - all that mattered in wartime. Arriving "spoiling for a fight," he eventually brought about the downfall of brilliant mathematician and fellow cryptanalyst Agnes Driscoll, one of the women whose story appears consistently throughout the book and who's recognized as one of the best cryptanalysts ever.

She devised a solution for cracking the Enigma machine, but the technology of the day wasn't adequate for carrying out her solution in a timely way. Bitter and angry, he even broke into her safe and intercepted messages she was working on solving just to one-up her. It also resulted in her being demoted for not developing the same deciphering machine that he did, forcing her into a kind of obscurity despite her brilliance in the field.

In a postwar oral history, Raven said of Aggie: "In retrospect I am convinced that Aggie Driscoll is one of the world's greatest cryptanalysts. I am convinced that the same accident that moved her from a beautiful woman to a hag affected her mind and that when she came back she couldn't solve a monoalphabetic substitution." Mundy comments, "Nobody knows how Agnes Driscoll felt. Nobody bothered to take an oral history from one of the greatest cryptanalysts in the world."

This was just one example of the towering sexism that these women faced not only during their work, but as part of what should have been a shining legacy. Even after the war, even after their wartime offices transitioned into the peacetime National Security Agency, these women were pushed from the spotlight, forced or encouraged to stay silent. 

It's far from the only story of women subjected to comments about their appearance and the nature of their work. They didn't have to lie much about what they were doing, since at this time it was easy enough to believe they were cleaning offices and sorting paperwork.

Ann Caracristi, another frequent subject, became first female deputy director of the NSA, "the federal entity the wartime code breakers begat." Their legacy is truly remarkable. Stories like Caracristi's and Driscoll's are quite thorough, while other women get less fleshed-out portraits. But's it's all fascinating, and Mundy has done such thoroughly researched work that I always felt like I was learning so much. It was extraordinary that despite the wealth of information it packs in, it was so beautifully written, completely understandable for non-technical types or without prior knowledge of the era's history, and as well-paced as a great novel. 

The only con was that it frequently skipped around in time and location, leaving me a little disoriented until I could identify the period and why the jump was made, but it remained confusing. Otherwise, it's excellent.

Virtually as soon as humans developed the ability to speak and write, somebody somewhere felt the desire to say something to somebody else that could not be understood by others.
Enlightening, always engaging, and long overdue history of the hard-working and admirably intelligent women who aided the Allied war effort so remarkably. If only every history book were written as compellingly as this one.

Code Girls is an interesting history of the role women played in intelligence work during World War II. Code breaking was tedious and difficult, and women were the backbone of the entire US cryptanalysis operation. Hired from a range of backgrounds, the women profiled in Code Girls had the unenviable task of figuring out what the enemy was saying and how they were saying it. Liza Mundy effortlessly weaves the necessary background information on the various ciphers and codes used by Nazi Germany and Japan with tales of the lives of women dedicated to cracking those codes.

Although this is the best overview I have read of cryptanalysis work during the war, Code Girls is not without it's faults. The personal impact this work had on the women was mentioned but seemed glossed over. Further, the book had an obvious and inescapable message that could be off-putting to readers who prefer their history without social commentary. There is no denying that women played a huge role in the overall success of the Allies, but there was also no need to constantly say so.

Overall, I really liked Code Girls. The book will seem familiar to anyone who has read Hidden Figures or Rise of the Rocket Girls; the men were sent to war, and the women worked in their place despite much hand-wringing from certain factions of society. As war wound down, women were "encouraged" to leave the workplace and the US military paid the price in a loss of expertise and the literal expense necessary to train their replacements. The struggles these women faced in the workplace resonate today; women still fight to receive equal pay and equal recognition for their work. The few minor issues I had with Code Girls did not detract from my enjoyment of the book, and I would recommend this to anyone with an interest in the roles women played during WWII.

Code Girls is a terrific oral history and more. Liza Mundy, a journalist, interviewed dozens of people, scoured government documents, studied contemporary newspaper and journal articles, and tapped a wealth of books, videos, and web pages to tell the previously untold story of the hundreds, possibly thousands, of women who cracked codes during World War II. Many were recruited from universities, some hired on with the U.S. Government, some joined the WACS or WAVES. They moved to the Washington, D.C. area and lived in government housing or shared quarters with other code breakers.

Mundy tells the history of wartime code breaking in the U.S. and describes some of the methods that were used. She follows the progress of the war and some of the women who worked long hours doing meticulous work, knowing that solving the ciphers quickly was critical and could mean life or death to troops halfway around the world. For many years they were anonymous, taking seriously the pledge of non-disclosure the government swore them to. When the cone of silence was finally lifted, many were still reluctant to talk, and sadly, many had died. Mundy talked with many of the women, and with surviving family members of others, was given access to letters and journals, and to the many colorful memories so many of the women had.

I enjoyed reading about the decoding processes and the evolution of codes during the war, as well as the more personal side of the women's stories. Mundy dug up fascinating details such as what the women did during their free time (one group of women bought a sailboat and spent their free time floating on the Potomac), the attitudes of the civilian and military men to working with so many women, and what the women did after the war.

A well researched and thoroughly documented account of a story that has too long been untold.

(Thanks to NetGalley and Hachette for a digital review copy.)

I liked the premise of the book, Female code breakers in World War II. Yet the author meanders so far into left field that there is an entire chapter on letters between one female and a boyfriend. The information was there and it felt like the author was just scraping the surface of the information out there.
I believe that the book would have been better if it had centered on 3 to 4 code breakers instead of throwing names and places at the readers.
Overall, a disappointing book that had promise.

Code Girls is far and away the BEST non-fiction I've read this year, if not in the past five years. Following the style of Hidden Figures in showing just how much work women have done to make our country what it is today, Liza Mundy reveals the women behind the code-breaking operation during World War II. During her research, she asked for documents to be declassified (some successfully, some not), giving us access to a whole new world of information about the lives of women during the war that they were never allowed to talk about.

What struck me most about this book is how well the author formats the narrative; she gives plenty of background information in the field of cryptanalysis, the context of what was happening during World War II at various times, and the context of just what the military was doing in order to combat the Axis nations. Within that, she follows the lives of a few women who left their normal lives to work for the government and help the war effort by joining a super secret project that broke codes for the military. Because of the way it's written, you get both the full context of what's happening and what the work the women are doing means, but you also get the human element of being able to relate to specific women who served as codebreakers, which is such a great balance to have in a non-fiction. It really helps it to become a page-turner and I was enthralled.

I never realized how much I didn't know about the US World War II effort; I would poke at my husband throughout the day to share the most interesting tidbits and tell him about what I was learning; it almost made me feel like a little kid again, discovering information that fascinated and enthralled me. And, of course, it's so great to hear the stories of women who were rock stars but never able to tell anyone about their accomplishments; it's humbling to read about how much work they did and the sort of conditions they put up with in order to simply help us win the war.

This book is everything -- heartbreaking, inspiring, emotional, and intelligently researched. I'm going to be buying copies of this for friends for Christmas this year, because this is a story that people need to know.

This story about the "clandestine mail reading" business during WWII is a pleasure to read and very much in keeping with the recent spate of books about women's contributions to American history.

The book begins with a bit of background on the history of American cryptanalysis, which gained steam after WWI. Then came the unprecedented scale-up after Pearl Harbor, and the work that went into cracking the Japanese codes. I got a bit bogged down trying to understand the minutiae of how messages are encoded, and then how cryptanalysts worked backwards to try to gain entry into enemy messages. Mundy did a good job of explaining the process, but I hope that the final version of the book includes some pictures or illustrations to help readers understand (I read a pretty basic advance copy). I was very interested in the ways that the intelligence departments gained information in a sideways manner, for instance studying the patterns of communications traffic and the stylistic format of the messages. I wish that there had been more about code breaking in the European theater, but breaking Enigma appears to have been done primarily by machine rather than through human analysis. I was fascinated by the use of communications traffic to create a phantom army to confuse the Germans about D-day.

I love that we got to follow several women closely through the entire war, and that Mundy included detail about their personal lives as well as their war jobs. Mundy's writing is clear and readable, and the story she tells is first-rate. I got a little bit confused jumping back and forth between the Army and Navy code breakers, and back and forth in time, but Mundy generally provided enough context and detail to get me back on track. These were incredible women who helped provide desperately needed information to win the war.

Code Girls was billed as similar to Hidden Figures and other recently released books and movies. In subject matter, this is correct. The book talks about the role young, intelligent woman played in the United States code-breaking operation during World War II. As opposed to the centralized focus of Hidden Figures-the book tends to jump around and back and forth profiling many different woman and some men. While there is something of a core of people they keep coming back to, it wasn’t as focused as they must have liked.

That being said, it is a very interesting look at how woman’s role in World War II both challenged the traditional assumption of women’s place in society and how the war was something that altered American society forever. It’s a solid book, but didn’t quite grab me the way the books and movies this is compared to did.

This book presented anecdotes about the individual code-breakers and World War II history in a somewhat random fashion, but the material was fascinating, and the author had obviously done extensive research.

Cyberwar, 1940's Version


Codebreaking is something Americans have just always been good at. Many of the wars and serious situations the US has found itself in were greatly mitigated by the reading of the other guy’s mail. WWII was no exception to that, and US Intelligence regularly read the most secret communications of both friends and enemies.

In Code Girls, Liza Mindy examines a little-known part of that battle, namely the contributions made by women in this effort. The obvious comparison to this book is the movie Hidden Figures, and I would describe this book as a superset of that movie. It expanded on many of the areas touched on in the movie, and added a bit more technical detail about the work being done.

=== The Good Stuff ===

* The book is written in a lively tone, and the many plots and subplots keep moving. I read the book in a day or two, since it captured my attention and didn’t let go. There are quite a number of named characters, but most of them only hang around for a chapter or two, so the plot doesn’t get confused or overly complicated.

* I suspect a lot of material that the author gathered didn’t make it into the book. You can almost feel the struggle for how much technical detail to include. Adding more detail lengthens the book, gives the reader a better feel for the work that was done, but probably bores some people. More technical people such as myself found the lack of detail a bit frustrating, and I wandered off to google my way to enlightenment. All things considered, I believe Mindy found a nice balance and ended up with a readable and sufficiently detailed book for the majority of readers.

* The book is about a lot more than codebreaking. The author gives us a glimpse of the difficulty of wartime relationships, the trials faced by the first women in various civilian and military roles, and the difficulties the women faced (as did everyone) finding lodging, food and basic survival necessities in wartime America.

* One of the more fascinating parts of the book was watching the women “lose their innocence”. They mostly came to Washington as amateurs, answering the call of duty for mathematically-talented people to perform calculations with little context of the big picture. Later, they found themselves intimately involved with people doing the killing and being killed. They knew the feeling of targeting a specific submarine, freighter or even Japanese Admiral, and seeing the results the next day. No one left Washington quite the same as when they arrived.


=== The Not-So-Good Stuff ===

* I found myself wanting more details. The German Enigma and Japanese Purple coding machines were remarkable for their time, and should have provided nearly foolproof protection for sensitive information. But the Americans and their allies broke into every one of these systems, and quite often had communications decoded before the intended recipient. This was possible because the people using the codes made some costly mistakes, and because the code-breakers made some incredible deductions and leaps of logic. The book only scratched the surface.

* The narrative can make some abrupt transitions, and these force the reader to do a little independent research of have some prior knowledge. For example, with no preamble or explanation, the book begins discussing American efforts to clone and improve the “bombe”. Readers familiar with WWII codebreaking will recognize this machine as an early computer, optimized to break cipher settings on the German Enigma machine. If you didn’t know what one was, and how complex it was, this section lost a lot of context.

=== Summary ===

I enjoyed the book, and learned quite a bit from it. While the book is nominally about the new female codebreakers, it turns in to a marvelous cross-section of life in wartime Washington, including the struggles of day-to-day life and the issues faced by the first female employees and soldiers.

Anyone with an interest in this area will enjoy the book, and it is written in simple enough language that the mathematics of codebreaking is explained well enough that most anyone could appreciate it.

Liza Mundy has written a compelling, well researched history that reads like a novel. The women who were recruited to do cryptanalysis during World War II were an extraordinary group who were intellectual, committed to the war effort, and able to take the lead and break codes that laid open the communications of the German and Japanese armed forces. It is not hyperbole to say that these women were instrumental in the Allied forces winning the war.
This book should be required reading for everyone! It is important to see these women finally getting the recognition they deserve.
In the notes and sources, there is a treasure trove of information that can be easily accessed, including oral histories!
Code Girls should go to the top of your to be bought and to be read lists!

Mundy introduces us to a remarkable group of women who, in large part, were pivotal in cracking enemy codes during WWII and consequently saving potentially millions of lives. She paints pictures, some more fulsome than others, of brilliant women who despite their splendid success in times of critical need, were not usually treated as well as their male counterparts. And once the war ended, most of the Code Girls were unceremoniously dismissed either to retreat to teaching or to motherhood. Mundy has done a masterful job of taking an enormous amount of research material and producing a coherent and riveting account.

This well researched book signifies a period of war where momentous changes occurred. And, I thought it interesting the way the story was told in flashbacks at times before WWII to show these differences.

It was apparent that artistic hobbies were considered a good sign of code breaking. Schoolteacher's and young college women were looked at closely for code breaking, as they were often unmarried, and able to adapt more easily. Women interested in serving, freely took an loyalty and secrecy oath. Even though, at that time, they were not clear on the exact purpose as to why they were being recruited. Women felt it important throughout the war to do their job well, while still doing everything in their power to keep up the morale of the men.

This is cleverly written. It shows life was moment to moment. This story pointed out the humor, romance and betrayal during wartime, and the way loss was honored.


These 'Code Girls' had great loyalty, discipline and focus. The study of coding and mention of false and non carrying addition and looping was entirely intriguing. As was the deciphering and deception program's with real traffic and fake traffic. Many women took these secrets to their graves. And we see the turmoil and struggle of this life altering decision that led to the wars end and our nation's gain. I felt this book was a excellent read and do highly recommend it.