C1 Lesson: The Codebreaker History Almost Forgot

Level: C1 (Advanced)

Content Objective: Students learn the story of Elizebeth Smith Friedman, an American codebreaker whose secret wartime work against Nazi spies was credited to someone else for decades, and consider how credit and secrecy shape the historical record.

Language Objective: Students learn to combine the passive voice with the past perfect to describe actions completed before another point in the past, and to recognize how the passive can hide or highlight who is responsible.

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1. Reading Section

As the war in Europe drew to a close, J. Edgar Hoover, the director of the FBI, launched a publicity campaign. His bureau, it claimed, had led the code-breaking effort that had crushed a network of Nazi spies in South America. A magazine article and a publicity film told the story; neither mentioned Elizebeth Smith Friedman, the cryptanalyst whose team had done much of the decoding. She was in no position to object. Her wartime work had been classified, and she had been bound by an oath of secrecy that she would keep until her death.

Her path to that moment had begun three decades earlier, in an unlikely place. In 1916, Elizebeth Smith, an Indiana-born graduate in English literature, had taken a job at Riverbank Laboratories, a wealthy businessman’s estate in Illinois, where she was asked to help prove that Francis Bacon had secretly written Shakespeare’s plays. The project was a dead end, but it introduced her to cryptology, and to William Friedman, whom she married in 1917. When the United States entered the First World War, the couple were put in charge of a new department of ciphers at Riverbank, and government personnel were sent there to be trained.

In the 1920s, the Coast Guard, which had been given the task of stopping smugglers along the American coasts, faced a new problem: rum-runners were coordinating their shipments by radio, using coded messages. Friedman was hired to decipher the backlog. Working largely by hand, she solved more than 12,000 messages in about three years, and her work contributed to 650 criminal prosecutions. By 1931, she had been placed in charge of a codebreaking unit, the only one in the country ever to be managed by a woman.

When war came, her unit was transferred to the Navy and turned against a new enemy. Nazi Germany was running a clandestine network across South America, and there was concern that Germany might eventually threaten the United States through Latin America. The FBI had been given responsibility for countering it, but the only American agency with experience in tracking secret radio traffic was the Coast Guard. Friedman’s team solved a series of German ciphers, including versions of the Enigma machine, and decoded around 4,000 messages sent on 48 radio circuits. After the ring was broken, Argentina, Bolivia, and Chile broke with the Axis powers and sided with the Allies.

Friedman was irritated by what she considered the FBI’s sloppiness. When its agents rounded up spies in South America, the Germans were alerted that their codes had been broken, and the new ciphers they introduced undid much of her team’s earlier progress.

When the war ended, the credit was claimed by someone else. The oath she had signed with the Navy prevented her from objecting, and she titled her unpublished memoir Footnote to History. For decades she was remembered chiefly as the wife of the more famous William Friedman, although it was she who had introduced him to codebreaking. Her wartime work was not declassified until 2008, twenty-eight years after her death.

Recognition came posthumously. She was inducted into the NSA’s Hall of Honor in 1999, and in 2019 the US Senate passed a resolution honoring her legacy. In 2020, the Coast Guard announced that it would name a cutter after her, although the ship was canceled in 2025 during a contract dispute. Her story suggests that history often follows those who are able to speak: Hoover could publicize his version of events, but Friedman could not reply, and for decades the record reflected that imbalance.

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2. Vocabulary Section

Word / Phrase	Meaning	Example
cryptanalyst	a person who breaks codes and ciphers without knowing the key	The cryptanalyst spent years studying the smugglers’ messages.
decipher	to work out the meaning of a coded or unclear message	Friedman was hired to decipher the backlog of messages.
clandestine	done in secret, especially because it is illegal or forbidden	Germany was running a clandestine network across South America.
classified	officially secret, with access restricted by a government	Her wartime work had been classified.
declassify	to officially make secret information available to the public	Her wartime work was not declassified until 2008.
claim credit (for)	to state that you were responsible for something and deserve praise for it	When the war ended, the credit was claimed by someone else.
oath	a formal, serious promise, often one that legally binds a person	She had been bound by an oath of secrecy.
posthumously	after a person’s death	Recognition came posthumously.

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3. Example Sentences (Target Grammar in Use)

• Her wartime work had been classified, and she had been bound by an oath of secrecy that she would keep until her death.
• In the 1920s, the Coast Guard, which had been given the task of stopping smugglers along the American coasts, faced a new problem.
• By 1931, she had been placed in charge of a codebreaking unit, the only one in the country ever to be managed by a woman.
• The FBI had been given responsibility for countering it, but the only American agency with experience in tracking secret radio traffic was the Coast Guard.
• When its agents rounded up spies in South America, the Germans were alerted that their codes had been broken.
• When the war ended, the credit was claimed by someone else.

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4. Grammar Section

Passive Voice + Past Perfect

The passive voice (be + past participle) puts the receiver of an action in the subject position, which lets a writer focus on what happened rather than on who did it. The past perfect (had + past participle) shows that an action was completed before another point in the past. Combined as had been + past participle, the two forms let a narrative look back at what had been done to a person or thing before the main events, often without naming who did it.

Form	Function	Example
passive voice (be + past participle)	focuses on the action or the person affected; the agent may be unknown, unimportant, or left out	Her wartime work was not declassified until 2008.
past perfect (had + past participle)	an action completed before another point in the past	The oath she had signed with the Navy prevented her from objecting.
past perfect passive (had been + past participle)	something done to a person or thing before another point in the past	The FBI had been given responsibility for countering it.

Quick Tip: Notice that an agentless passive can hide responsibility. “The credit was claimed by someone else” names no one, while “Hoover claimed the credit” does. Skilled writers choose deliberately: they keep the agent when responsibility matters, and they omit it when the doer is unknown or unimportant.

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5. Comprehension Questions

A. True or False

1. Hoover’s publicity campaign gave Friedman’s team credit for the codebreaking.
2. Friedman’s first codebreaking work involved a project connected to Shakespeare.
3. The Coast Guard was the only American agency with experience in tracking secret radio traffic.
4. Friedman’s wartime work was declassified while she was still alive.

B. Short Answer

5. Why was Friedman unable to correct Hoover’s version of events?
6. Why was the Coast Guard, rather than the FBI, well placed to deal with the South American network?
7. What might the title of Friedman’s unpublished memoir, Footnote to History, suggest about how she saw her place in the historical record?
8. How does the sentence “the credit was claimed by someone else” illustrate the grammar point of this lesson?

C. Fill in the Blank / Transform — Use the passive voice, the past perfect, or the past perfect passive, as appropriate. For items 11 and 12, rewrite the sentence.

9. By the time the war ended, Friedman’s unit ___ (transfer) to the Navy.
10. Her wartime role ___ (not / declassify) until 2008.
11. Rewrite in the passive voice: The FBI’s arrests alerted the Germans.
12. Rewrite in the past perfect passive: By 1931, the Coast Guard put Friedman in charge of a codebreaking unit.

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Next lesson: C1 — “The Experiment That Went Too Far”