The Fifth Column
...enemy sympathizers in America & how to research ancestors during a time of democratic uncertainty...
We've heard about World War II and maybe a little about World War I, but today, let’s discuss the space between the two Great Wars. It was a twenty-one-year period that began in 1918 and ended in September 1939. Known as the "interwar period," a great deal of history took place in those years. From the Roaring Twenties to the Great Depression, the Treaty of Versailles to the rise of Modernism in art – those twenty-one years redefined what it meant to live in America as it was before World War I to what it would become after World War II.
It was a time of immense political instability and the rise of authoritarianism around the world. That is where this story begins.
Between World War I and World War II the world witnessed an unprecedented rise in what intelligence agencies termed “Fifth Column” activities across the United States. Named after the Spanish Civil War term for internal subversives, the Fifth Column represented foreign agents, sympathizers, and domestic extremists who worked to undermine American democracy from within. It is an era of political turbulence, economic upheaval, and rising global tensions that created a fertile ground for various forms of internal subversion that would shape American security policy for decades to come.
The Post-WWI Security Landscape
The end of World War I did not bring peace to America’s internal security concerns. The 1917 Russian Revolution had sparked the First Red Scare which led to the Palmer Raids and mass deportation of “radicalized immigrants” in the United States. (Some of whom were American Citizens.) Led by A. Mitchell Palmer, the raids were designed to remove trouble makers, socialists, and many sympathizers of what was happening in Russia – namely the Russian Revolution. Panic was widespread, creating a soapbox for any anti-immigrant voices to speak up – including Senator Duncan Upshaw Fletcher who helped to pen a bill that stated, even native born Americans should be “deported to Gaum” if they weren’t acting American enough.
By the 1920s, federal authorities were increasingly concerned about communist infiltration. The Palmer Raids of 1919-1920 demonstrated both the government’s willingness to act against suspected subversives and the constitutional challenges such actions posed.
During this period, between the 1920s and 1930s, several distinct Fifth Column networks emerged. Each one had their own different ideological motivations, but, in the end, they shared a common goal: undermining American institutions.
These goals included communist agents directed by the Soviet Union, fascist sympathizers aligned with Nazi Germany and Mussolini’s Italy, and various domestic extremist movements that sought to exploit America’s vulnerabilities.
Groups like the Ku Klux Klan, Silver Shirts a paramilitary group emulated Nazi Brown Shirts, the Black Legion a secretive paramilitary faction responsible for assassinations, bombings, and arson that targeted minorities, labor activists, and political opponents, operating primarily in the Midwest, the Khaki Shirts a group of radicalized veterans, this militia aimed to stage a coup against the U.S. government, and the lessor known Hinomaru Kai (Rising Sun Flag Society), a Japanese ultranationalist group that operated until WWII, promoting imperial loyalty among immigrants.1
The Communist Network
Soviet intelligence services, primarily the NKVD and GRU, established extensive networks throughout the United States during this period. These operations went far beyond simple espionage, encompassing efforts to influence American politics, labor movements, and intellectual circles. They concentrated on recruiting high level Americans, like Harry Dexter White (U.S. Treasury Department), Lauchlin Currie (economic adviser to President Roosevelt), and Judith Coplon (U.S. Justice Department) to help further their objectives of political espionage, penetration of U.S. Government agencies, the spread of propaganda to misinform and disrupt public opinion, and to set up and maintain active networks around the county. The Communist Party USA, while officially a domestic political organization, served as both a recruitment pool and operational base for Soviet intelligence.
Some key figures, like Whittaker Chambers and Elizabeth Bentley, would later reveal the extent of communist penetration into government agencies, including the State Department, Treasury, and various New Deal programs.
One of these, the Ware Group, a covert organization of Communist Party USA (CPUSA), was active in Washington D.C. during the 1930s, recruiting young idealistic government employees who believed they were working for progressive causes while actually serving Soviet interests.
The Communist Fifth Column was particularly effective in penetrating labor unions, academic institutions, and Hollywood. Labor unions like United Auto Workers (UAW) and the Steelworkers Organizing Committee (SWOC) were targeted by the Communist Party USA (CPUSA), as were many student led organization on College and University campus, and International Alliance of Theatrical and Stage Employees (IATSE) in Hollywood.

The appeal of communist ideology during the Great Depression, when capitalism was failing the working class, provided cover for recruitment efforts. Many Americans who joined these networks genuinely believed they were working to create a more just society, unaware of the broader intelligence operations they were supporting.
The Fascist Threat
As Nazi Germany rose to power, German intelligence services launched their own Fifth Column operations in America. The German-American Bund, led by Fritz Kuhn, represented the most visible face of Nazi sympathizers, organizing rallies and spreading propaganda throughout the country. At its peak in the late 1930s, the Bund claimed over 25,000 members and operated camps where children were indoctrinated with Nazi ideology.

More dangerous were the covert operations conducted by German intelligence. These included efforts to sabotage American defense production, steal military secrets, and influence American public opinion to keep the United States out of the war in Europe. The Duquesne Spy Ring, led by Frederick "Fritz" Duquesne, a South African-born adventurer and soldier of fortune, was the largest Nazi spy network ever uncovered in the United States. Broken up by the FBI in 1941, the disbandment of the Duquesne Spy Ring resulted in the most convictions for espionage in American history, including the arrest of thirty-three agents working to steal military and industrial secrets.

At the same time, Italian fascist agents in groups like the Dante Alighieri Society, were also operating in the United States, though their networks were generally smaller and less sophisticated than their German counterparts. They focused primarily on propaganda efforts within Italian-American communities and intelligence gathering on American military capabilities.
Domestic Extremism
The interwar period also saw the rise of various domestic extremist movements that, while not directly controlled by foreign powers, shared many goals with America’s enemies. The Silver Legion of America, led by William Dudley Pelley, promoted fascist ideology and anti-Semitic conspiracy theories. Father Charles Coughlin’s radio broadcasts reached millions of Americans with messages that often aligned with Nazi propaganda themes.
The Ku Klux Klan, while focused primarily on racial issues, they also promoted isolationist and anti-communist messages that served the interests of both German and Soviet intelligence services. These domestic groups provided cover for foreign agents and created an atmosphere of political extremism that made traditional espionage easier to conduct.
Government Response and the Birth of Modern Counterintelligence
The Roosevelt administration’s response to fifth column activities laid the groundwork for America’s modern intelligence apparatus. In 1936, President Roosevelt secretly authorized J. Edgar Hoover’s FBI to investigate “subversive activities,” marking the beginning of systematic domestic counterintelligence operations and setting the groundwork for the second Red Scare that would later debilitate the Nation during the 1950s.
The FBI developed new techniques for surveillance, infiltration, and disruption of fifth column networks. The bureau recruited double agents, intercepted communications, and built extensive files on suspected subversives. These operations, while often successful in neutralizing genuine threats, also raised serious questions about civil liberties and the balance between security and freedom.
The Dies Committee, or the House Un-American Activities Committee (HUAC), established by Texas Congressman Martin Dies, Jr., was the latest House Committee created to investigate alleged disloyalty and subversive activities on the part of private citizens, public employees, and those organizations suspected of having communist ties. Its predecessors included: the Overman Committee (1918-1919), Fish Committee (1930), and the McCormack–Dickstein Committee (1934–1937). The Dies Committee officially began investigating fifth column activities in 1938 and was operational until 1944. While the committee did succeed in exposing subversion networks and raising public awareness of the communist threat, their work was often politically motivated and sometimes reckless, targeting labor movement and union leaders.
The Media and Public Opinion
The American press played a crucial role in both exposing and sometimes inadvertently assisting fifth column activities. Newspapers like the New York Times and Washington Post published investigative reports that revealed the extent of foreign penetration, while other publications either ignored the threat or actively promoted extremist ideologies.
Radio emerged as a particularly important battleground. While Father Coughlin used radio to spread fascist-leaning messages, other broadcasters, like "The American Forum of the Air," which aired on CBS, worked to educate the public about the dangers of fifth column activities. The development of public opinion polling during this period also allowed researchers to track American attitudes toward foreign ideologies and assess the effectiveness of propaganda efforts.
Impact on American Society
The fifth column's efforts to undermine American society between the wars contributed to a growing atmosphere of suspicion and paranoia that would later manifest in McCarthyism. The experience also led to significant wariness of American immigration policy, with the country leaning into the Immigration Act of 1924, which had already limited the amount of immigrants permitted into the United States from Asia and South East Europe. The fear of incoming immigrants working as part of the fifth column, essentially of being infiltrating spies, led to tightened restrictions that would prevent the entry of those potential subversives. It wouldn’t be until 1948 that the United States would pass the Refugee Act – nine years after MS St. Louis carrying 900 Jewish refugees fleeing Nazi persecution was refused entry into the US and sent back to Europe.
Educational institutions also continued to be a battleground for competing ideologies, with both communist and fascist agents working to recruit students and faculty. The academic freedom that had characterized American universities came under increasing scrutiny, as administrators struggled to balance openness with security concerns. This atmosphere of suspicion led to self-policing, increased scrutiny of foreign students, and sometimes the dismissal or marginalization of faculty members perceived as disloyal or foreign-born – especially those of German, Italian or Japanese descent.

Lessons and Legacy
The major concern was that a “fifth column” of Nazi and other fascist sympathizers, or agents, would weaken the democratic unity making up American society. Their activities were designed to create confusion and ultimately reduce the nation’s ability to respond to external threats—thereby making the United States more vulnerable, not necessarily to keep it out of the war, but to ensure the country would be less effective if or when it did join the conflict. While foreign agents did succeed in invading the United States, like in 1942 when eight German Agents landed on the coast of Long Island with the intent of industrial sabotage as part of a larger operation known as Operation Pastorius or the far-right Christian Front, led by Father Coughlin who’s anti-sematic, pro-fascist propaganda led to seventeen members being arrested after an attempt to overthrow the government in June of 1944. All of this on top of infiltrating government agencies and stealing secrets, yet in the end they ultimately failed to undermine American democracy or prevent the United States from both entering World War II on the side of the Allies and remaining vulnerable to the intentions of Axis threats.
The experience taught American policymakers important lessons about the nature of modern threats and the need for sophisticated counterintelligence capabilities laying the groundwork for the United States path into the Cold War. The activity also highlighted the ongoing tension between National Security and Civil liberties that continues to challenge American democracy today.

The fifth column threat between the wars represented a unique moment in American history when the country faced simultaneous challenges from communist and fascist agents while also dealing with domestic extremism – a recipe for national upheaval and fractured infrastructure. It was a transitional period that pulled away from the mass immigration movements to the United States that began in the last 1800s, finally ending in the 1920s with the Immigration Acts.
Yet, while the conversation of Fifth Column activities tends to be postmarked by the decades sandwiched between World War I and World War II – the threat they carried into our history didn’t end with the bombing of Hiroshima and Nagasaki or the liberation of Auschwitz. The activity transmorphed into post war/Cold War activities like Rosenberg Trial in the 1950s, the anti-imperialists pro-Marxist Weathered Underground in the 1960s/1970s, Aldrich Ames and Robert Hanssen’s involvement with the Soviet Union in the 1980s/1990s, and even the attacks carried out at Pulse Nightclub or the Boston Marathon which were carried out by an ISIS and al-Qaeda sympathizers.
Understanding this period provides insights into how democracies can respond to internal threats while maintaining their essential character. As the United States continues to face new forms of subversion and extremism, the lessons learned from confronting the fifth column between the wars remain highly relevant to contemporary security challenges. Plus, it demonstrated the types of adversity and challenges our ancestors faced while they were alive.
Key Resources for Learning About Fifth Column Activity
Historical Maps and Propaganda
"The Fifth Column Menaces America on a Thousand Fronts" (1941): This detailed propaganda map illustrates the fear of Communist, Nazi, and Fascist infiltration in the U.S. It identifies alleged headquarters, training camps, and literature centers, and is available at institutions like the Cornell University Digital Library.
Digital Libraries and Archives: Cornell University, the New York Public Library, and Columbia University hold digital or physical copies of this map and related materials.
Books and Scholarly Articles
Academic Journals: Articles on the topic are available in history and political science journals. For example, MDPI’s Religions journal published “The Most Dangerous Fifth Column in the Americas:” U.S. Media and the Axis Fifth Column during WWII.
Books: Look for works on the Red Scare, the German-American Bund, Japanese internment, and the history of domestic surveillance in the U.S.
Primary Source Collections
House Un-American Activities Committee (HUAC) Records: These documents, held at the National Archives, detail investigations into suspected subversive organizations and individuals.
FBI Records: Declassified FBI files on organizations like the German-American Bund, the Silver Shirts, and the Christian Front are available through the FBI’s online FOIA (Freedom of Information Act) Vault.
Newspaper Archives: Historical newspapers such as The Washington Post and The New York Times contain contemporary accounts of suspected fifth column activity, including editorials and investigative pieces.
Records for Genealogical Research
Census Records and Alien Registration Files
U.S. Census (1920, 1930, 1940): Can help identify individuals suspected of or investigated for subversive activities.
Alien Registration Files (1940–1944): Non-citizens were required to register, and these records may indicate surveillance or suspicion.
Military and Draft Records
World War I and World War II Draft Registration Cards: May include notes about loyalty or investigations.
Military Service Records: Sometimes contain annotations about loyalty investigations or suspected subversion.
FBI and Justice Department Files
FBI Case Files: Available through FOIA requests, these can include investigations of individuals or groups suspected of fifth column activity.
Justice Department Records: May include indictments, court cases, and internment records.
Internment and Detention Records
Japanese American Internment Records: The National Archives holds records of those interned during WWII, often based on suspicions of fifth column activity.
Enemy Alien Detention Files: For German, Italian, and other nationals suspected of disloyalty.
Local and State Archives
State Police and Local Law Enforcement Records: May contain surveillance reports or investigations of suspected subversives. (search the area you are researching)
State Historical Societies: Often hold collections related to local reactions to suspected fifth column activity. (search the area you are researching)
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There were many domestic groups working hard to dismantle the American Democratic State. They promoted ideologies such as white supremacy, anti-Semitism, anti-immigration, and authoritarianism, often employing violence, propaganda, and political infiltration. I’ve only listed a very small handful in this article.