The Resister: This Milwaukeean Smuggled Secrets Out of Nazi Germany

How Mildred Fish-Harnack gave everything fighting Adolf Hitler’s regime from the inside

When a Nazi military tribunal sentenced Milwaukee native Mildred Fish-Harnack to die by guillotine in January 1943, no one in her hometown had any inkling. Not of her arrest, nor of her sickly existence in a German prison, nor of the intense danger that surrounded her for every moment of the previous decade.  

Her family had mostly left the area by then, and anyone who might have recalled the bright and introverted young “Millie” from her youth in the city would have no idea of her secret life in wartime Germany.  

Her actions there, once uncovered, had so infuriated Adolf Hitler that he personally intervened in her trial. Nothing short of death by beheading was an appropriate punishment for her acts of sabotage against the Nazi regime, Hitler insisted. She would be the only American citizen beheaded by the Nazis during the war, and the only woman executed on Hitler’s personal command.   

Her sentence was carried out on Feb. 16, 1943. It took three months for news of her death to reach the U.S., and decades more before the secret records emerged that helped to tell her story.

Mildred Fish-Harnack, 1923; Photo via public domainx

MILDRED FISH was born in a Wisconsin Avenue boardinghouse in 1902 to William Fish and the former Georgina Hesketh. Georgina was smart and ambitious. She had taught school and worked as a typist in Washington County before moving to Milwaukee with her three older sisters as a teenager. William won her heart with a dashing figure and fashionable dress, but his professional habits were considerably less attractive. He drifted between jobs that seemed unable to hold his interest; his drinking was one of the few consistent things about him. The family moved often and had little. 

In her diary, Mildred’s sister Harriette set scenes later explored in Shareen Blair Brysac’s Resisting Hitler, a biography of Mildred: canoeing in Mitchell Park, swimming in the upper Milwaukee River, elephant rides at the zoo. Material treats were rare, but the Fish children had full access to the simple pleasures of the Socialist-minded “German Athens” that Milwaukee was in the early 1900s. As the youngest of the four, Millie often forged her own path, left to explore whichever pocket of Milwaukee to which the family had just moved. She read and sang, climbed trees and kept to herself.

When Mildred was 7, Harriette defied the expectations of her family’s situation and was accepted at the University of Wisconsin in Madison. When Mildred was 14, by then a student excelling at West Division High School, her mother defied her era’s standards and left her increasingly unreliable husband, taking Mildred to Madison to live with Harriette. He begged for a reunion and Georgina briefly conceded before leaving him for good. In January 1918, during one of the worst snowstorms to hit Milwaukee in 20 years, William was found dead in a barn. Mildred would later cite the cause of death as “galloping consumption.” Shortly after William’s death, Mildred and her mother moved to Chevy Chase, Maryland, where Mildred completed high school.

In 1921, Mildred followed the tradition set by Harriette and enrolled at UW. Bright, athletic and pretty, Mildred stood out in her own quiet way. She loved the splendid pastoral areas near Madison and spent hours hiking. She studied journalism and wrote for the Wisconsin State Journal. In 1925, she earned an English degree and stayed in Madison as a graduate student and instructor. During one of her lectures, a German-born student named Arvid Harnack mistakenly walked into her class, looking for another room. He was instantly taken with Mildred. Arvid was shy and unassuming, unlike most of the young men Mildred knew at school. He already held a Ph.D. in law and was working on another in economics. He said nothing to her during their first mistaken encounter, but a few days later, he showed up with a handful of wildflowers at the home where Mildred rented a room. He asked if he could take her canoeing on Lake Mendota. 

Six months later, Mildred and Arvid were married on a small dairy farm just outside of Madison. Arvid later returned to Germany, and in June 1929, Mildred followed. Four months later, the American stock market crashed. The global panic further stoked the nationalist resentments that Germany’s right wing had held since their perceived humiliation at the end of the First World War. Previously-fringe groups made significant electoral gains, including Hitler’s Nazi Party.  

A commemorative stamp honoring Mildred Fish-Harnack and her husband, Arvid, issued by East Germany’s Deutsche Post in 1964; Photo via pbulic domain

But when Mildred arrived in Germany, the high intellectual spirits of the early Weimar years still pervaded. The interwar period was a boom time for arts and progressivism in Germany. Berlin, where she and Arvid settled, was a cultural haven, and Mildred loved the bustle of the urban center. She worked teaching English at the Berlin Night School for Adults, where classes were inexpensive, and textbooks and hot meals were free to anyone who needed them. She taught laborers her native language through literature and political theory. It was a grand time for Mildred, who had immersed herself in leftist and radical politics and thought with Arvid in Madison. Her friends in Berlin were similarly politically aligned. As the economic situation in German continued to deteriorate, Arvid became more enamored with the Soviet system and he and Mildred both became disillusioned with capitalism. Few in their circle took the Nazi threat seriously.  

By the summer of 1932, nearly three full years into the financial crisis, the Nazi Party was the largest seat-holder in the Reichstag. In January 1933, Hitler was appointed chancellor and throughout the rest of the year, he assumed near-totalitarian powers over Germany. Elections were essentially rendered meaningless. Books were burned. Women’s rights were remade in the image of the Nazi ideal: encouraged by propaganda and government-issued loans to have as many children as possible (the loans were entirely forgiven after four children are born, and a family was exempt from income tax at six children). Abortions were outlawed for women of Aryan heritage (similarly, the bonus for childbirth did not apply to those without “pure blood”), considered as crimes against the future prowess of the German race. Mildred became pregnant that year. Near poverty on her and Arvid’s meager wages in Berlin, she used $56 mailed to her by Georgina to travel to London and terminate the pregnancy. Rebecca Donner, in her 2021 biography of Mildred, All the Frequent Troubles of Our Days, called the procedure “an act of sabotage” against the Nazi regime. It would not be her last.

AROUND THIS TIME, Mildred and Arvid became involved in a small group of Nazi resistors, calling themselves the Circle. One early collaborator of theirs was arrested for distributing leaflets opposing the Nazis. He was beaten by the police and sentenced to a year in a concentration camp. Their first meetings were held at the Harnacks’ apartment, but even such moderately visible acts quickly became too dangerous. Mildred recruited new members at the night school with the utmost caution. She’d usually lend someone she considered a possible sympathizer a book. Later, she’d ask carefully worded questions about the work, feeling for any tiny threads of recognition. Outwardly, both she and Arvid were supporters of the Nazi regime. Both signed their letters “Heil Hitler” – even as the letters were increasingly written in code. 

During this same period, Mildred, traveling in the small group of American women living in Berlin, made friends with Martha Dodd, the socialite daughter of President Franklin Roosevelt’s ambassador to Germany, William Dodd. Martha had connections to the literary world that impressed Mildred, and the two would eventually write a literary newspaper column together. Martha’s connections opened doors for Mildred that allowed for new sources of income – and new covers for international travel as an agent for a German publishing house. It also allowed for the potential smuggling of exit visas to those Mildred and the Circle needed to help escape the country.

Meanwhile, the resisters were publishing anti-Nazi literature as fast as they could surreptitiously acquire the needed supplies; even buying too many postage stamps at once could draw suspicion. They left leaflets at bus stops, in phone booths and at train depots, or mailed them to strangers in hopes of counteracting Nazi propaganda. They published material in French, Italian and Polish to reach imported laborers forced to work in munitions plants. Identification cards and exit papers were forged and safe houses created for Jews trying to escape the country. Mildred helped to craft the codes that were needed for communication as she continued to recruit more members. She and her comrades learned to hide tiny notes in the seams of clothing or inside jars of food that they sent into the labor camps. 

But by 1934, it was clear that the Circle needed to escalate their actions. That summer, the infamous Night of the Long Knives left nearly 200 of the Nazis’ political adversaries dead and Hitler declared his rule as superior to that of the courts. Hitler was soon in total control of the nation, its legal system and its military. In the wake of the purge, Arvid was placed in a job at the Reich Ministry of Economics. He officially joined the Nazi Party and was now privy to a wealth of state secrets. He kept the lowest possible profile at work, serving dutifully and with a bored demeanor that made him seem no more a threat than the office furniture. But Arvid had already made connections with Russian agents and was working to create a network to pass along valuable information.

In 1937, the same year that the SS opened the Buchenwald concentration camp, Mildred and Arvid traveled to the U.S. on official business. Mildred went on a short lecture tour, speaking on literary topics, but friends and family noticed a dire change in her once-sunny demeanor. She visited Milwaukee, but it didn’t seem like home anymore. She rarely smiled and refused to speak about what was happening back in Germany. She visited Georgina, who was deathly ill and living in Wauwatosa, but Mildred would not consider staying.

News of Mildred’s execution came to the United States three months after her death; Photos from Wisconsin Alumnus, courtesy of the Wisconsin Foundsation and Alumni Association; Milwaukee Weekly, Nov-Dec 1989; Milwaukee Historical Society; Public domain

She loved Germany. It was where she and Arvid had made their life together. She had hope that the bright and vibrant culture she had first encountered there, before the Nazis’ rise, could return. As a girl in Milwaukee, she had seen the cruel hand of nationalism at work: in the prejudice against a Jewish friend, in the backlash against Germans during the First World War. She returned to Germany and stayed, even after Arvid purchased a steamship ticket back to the U.S. that she could have redeemed at any time. Even, a few months after her return from the U.S., when word reached her that her mother had died. 

When a purge by Josef Stalin left the most important of Arvid’s Russian contacts dead, the Harnacks shifted their focus to the West. Mildred was friends with Louise Heath, wife of Donald Heath, an intelligence officer at the U.S. Embassy in Berlin. Shortly after the Germans invaded Poland in September 1939, Mildred made an arrangement with the Heaths to act as a tutor for their 11-year-old son, Donald Jr. Mildred did indeed tutor the boy, but he was also a conduit for passing secrets to the Americans. She slipped encrypted letters – on the surface, banal material like arrangements to meet up or recipes – into his backpack to take home to the embassy. Donald Jr. would even accompany Mildred as she met with contacts, lollygagging behind and playing by himself, knowing to whistle the “danger song” if any SS officers or other officials happened to be within sight.

By 1941, with the Nazis having already taken France, Arvid had established new contacts in the Soviet Union and was furiously passing information on the German economy and war plans. Early that year, Arvid had passed information saying that a German invasion of Russia was imminent. Stalin refused to believe that Hitler would go back on the non-aggression pact the two had signed in 1939, but six months after Arvid’s warning, the Nazis invaded. Similarly dire warnings about Hitler’s global ambitions were passed to the Americans – and also mostly ignored. 

Still, the Harnacks spent nearly all of their waking hours for the cause. With Arvid often out of the house on business – official or unofficial – Mildred worked deep into the night, using the obscure 1910 French novel Le Miracle du Professeur Wolmar to encode intelligence reports that would be sent both east and west.

THE INEVITABLE arrived in the spring of 1942. A Gestapo raid turned up a cipher pad – a clue that messages were being coded – used by someone in the Circle. After a copy of Professeur Wolmar was tracked down by a Nazi official in a Paris bookstore, it took a week to crack the code. And finally, in an encrypted message they had intercepted from the Russians, the Nazis had a list of names, Arvid and Mildred among them. 

The Harnacks ran, hoping to make it to Sweden, an island of neutrality in a world at war. When she was arrested by the Gestapo at a farmhouse in Nazi-occupied Lithuania two weeks later, Mildred was still carrying the steamship ticket to the U.S. that Arvid had bought for her five years prior. 

The scope of what Arvid and Mildred had been involved in was shocking, even to the most upper ranks of the Nazi Party. In all, the arrests resulting from the Professeur Wolmar code would number in the hundreds. 

Kept in wretched cells and fed starvation rations, Mildred and the others were interrogated and tortured before going to trial, where the outcome was largely considered a formality. Arvid was convicted and sentenced to death, but Mildred, in a surprise show of sympathy, was found to have been largely unaware of Arvid’s actions and sentenced to six years. Hitler, outraged that the only American among what the Nazis had dubbed the “Red Orchestra” had been shown leniency, ordered her to be tried again. Despite no new evidence against her, she was retried and convicted of treason. 

Death came for Mildred Fish-Harnack a month later, on Feb. 16, 1943 – some 15 months before American soldiers stormed the beaches of Normandy. By then, she was so sick with tuberculosis that she was barely able to stand, and she spent her final hours translating passages from a Johann Goethe poetry book into English. A priest was allowed to visit her at the very end. He smuggled her an orange and a photo of her mother. “The face of my mother,” Mildred wrote on the backside of the picture, “expresses everything that I want to say at this moment.” 

Matthew J. Prigge is the author of five books, including the forthcoming Opening Day in Milwaukee.


This story is part of Milwaukee Magazine’s October issue.

Find it on newsstands or buy a copy at

Be the first to get every new issue. Subscribe.