Nov. 15, 2025

The Alien Enemies Act: When Fear Became Law—and Never Left

The Alien Enemies Act: When Fear Became Law—and Never Left

Passed in 1798 as part of the notorious Alien and Sedition Acts, the Alien Enemies Act has outlived its controversial siblings — and it’s still on the books today. In this episode, I trace its origins in the fear and politics of the early republic, how presidents from Madison to FDR have invoked it in times of war, and what it means that this 18th-century law remains active in the 21st century.


From the tension between liberty and security to the ways old laws shape modern policy, this is the story of how a relic of the Federalist Era continues to echo through American history.

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SOURCES

Baker v. Carr | 369 U.S. 186 (1962) | Justia U.S. Supreme Court Center

Claire Prechtel Kluskens, “Internment of Enemy Aliens During World War I.” NGS Magazine Vol. 43, no. 2. April-June, 2017. (LINK)

Donald Trump. “Invocation of the Alien Enemies Act Regarding the Invasion of the United States by the Tren De Aragua.” March 15, 2025. (LINK)

Katherine Yon Ebright, “The Alien Enemies Act, Explained.” Brennan Center for Justice. Updated May 1, 2025. (LINK)

Rachel Treisman, “The Alien Enemies Act of 1798, explained.” All Things Considered. NPR. October 19, 2024. (LINK

Treaty of Alliance with France; 2/6/1778; Perfected Treaties, 1778 - 1945; General Records of the United States Government, Record Group 11; National Archives Building, Washington, DC. (LINK)

Terri Diane Halperin. “Immigrants and the Alien and Sedition Acts of 1798.” History Now. Issue 52. Fall 2018. The Gilder Lehrman Institute of American History. (LINK

“The Neighbors Not Enemies Act.” Japanese American Citizens League. (LINK)

“The Quasi-War with France (1798-1801),” USS Constitution Museum. (LINK)


“The XYZ Affair” American Battlefield Trust. Updated March 25, 2025. (LINK)

Hey everyone. Welcome back.

 

A few weeks ago I dipped my toe into what I call my civic history era with an episode dedicated to the history and prior usage of the Insurrection Act. In it, I outlined the context surrounding the law’s establishment and how prior presidential administrations have used it since its origins. You all seemed to really enjoy that episode and asked for more - so I am back with another ripped from the headlines history deep dive. 

 

On March 15th of this year, the president issued an executive order titled “Invocation of the Alien Enemies Act Regarding the Invasion of The United States by Tren De Aragua.” In the order, the president announced he was invoking the Alien Enemies Act to combat the illegal activities of a gang known as Tren De Aragua. This executive order instructed the Attorney General and the Department of Homeland security quote: “consistent with applicable law, apprehend, restrain, secure, and remove every Alien Enemy described in section 1 of this proclamation,” end quote. This had many Americans asking the question - what exactly is the Alien Enemies Act? 

 

So this week, I am exploring the Alien Enemies Act. What is it? How did it originate? And how have other presidents used it in the past?

 

Grab your cup of coffee, peeps. Let’s do this. 

 

To understand the Alien Enemies Act, it is important to understand the context and events surrounding its passage. First, the Alien Enemies Act is one of four laws passed in the summer of 1798 - during the administration of second president John Adams. Despite being a helpful ally during the American Revolution, tensions between the nascent United States and France had been growing steadily for several years - to the point where Americans were concerned about the possibility of going to war with their-once trusted ally. The issues pushing the countries toward the brink came out of the French Revolution. In 1778, the United States and France entered into a shared alliance where both countries agreed to support each other both militarily and financially. With the French Revolution, however, the monarchy that originally entered into the treaty was overthrown, leaving some in the United States government to argue that the removal of the monarchy basically voided the terms of the agreement. Thus, when war broke out between Great Britain and France, the United States declared its neutrality in 1792 – largely in an effort to placate both sides and keep the country out of foreign entanglements. 

 

Yet just two years later, the United States entered into the Jay Treaty – a trade agreement with Great Britain which angered the French. Thus, French privateers began seizing U.S. merchant ships trading with the British colonies in the Caribbean and there was legitimate concern that these seizures in southern waters would eventually head north and that the United States could be facing war with a pretty powerful enemy. When the United States tried to solve their tensions with the French government through diplomacy, they were given the run around and faced unreasonable demands including an attempt to solicit bribes from the American envoys before France’s Minister of Foreign Affairs, Charles-Maurice de Talleyrand would even consider meeting with them. While admittedly skipping a lot of detail and nuance, this impasse led what we know as the XYZ affair in the United States and furthered American suspicions about the potential for war with France. 

 

Mixed with the heightened fears of a potential war was the fact that thousands of immigrants had fled to the United States amidst the chaos and dangers of Europe. This included people from England and France who settled throughout the country, including  Philadelphia - still the nation’s capitol in 1798. It is estimated that roughly 25,000 French nationals lived in the capital city. There were French newspapers and boarding houses; french schools and restaurants. As Adams biographer and historian David McCullough described quote, “the French, it seemed, were everywhere, and who was to measure the threat they posed in the event of a war with France?” end quote. In this context, there was a real fear of the enemy within - what would happen, some worried, if the United States and France were to go to war? Would those thousands of Frenchmen take up arms in defense of their mother country and override the capital? There was also - to a lesser extent - concern about the quote unquote wild irish - those who migrated to the United States during the Irish Rebellion in 1798. 

 

As was the case during the signing of the Militia and Insurrection Acts, the Alien and Sedition Acts were passed when the United States was still very much a new nation. It had not yet developed the military nor the diplomatic channels that we have become accustomed to. So in addition to authorizing the commission of new naval ships to provide security against attack from the outside, the Alien and Sedition Acts were seen as mechanisms to safeguard the country from attacks from inside. As I mentioned at the start of the episode, the Alien Enemies Act was one of four laws passed during the summer of 1798. The other three were the Naturalization Act of 1798 which extended the period of time someone had to be in the country before seeking citizenship; the Alien Friends Act – which allowed the president to detain and deport foreigners, and the Sedition Act - which basically made it illegal to make malicious or false statements against the government and was the law that drew the most criticism. 

 

The Alien Enemies Act allows the president to deport or detain individuals who originate from another country when said individual comes from a country the United States is at war with and if they are considered a threat to national security. It essentially gives the president and the courts the power to control or remove quote unquote enemy aliens during times of conflict. The law as written states that during times of war after a presidential proclamation - or executive order - quote “all natives, citizens, denizens, or subjects of the hostile nation or government, being males of the age of fourteen and upwards, who shall be within the United States, and not actually naturalized, shall be liable to be apprehended, restrained, secured and removed, as alien enemies,” end quote. During times of war, the law allows the President to deport individuals without granting them due process - a hearing - solely based on where they come from. 

 

This authority is only accessible during times of a declared war between nations. And as a reminder it is Congress who has the sole authority to declare war. Despite our recent history, the last time the United States Congress declared war was 1942 when the country decided to enter World War II after the bombing at Pearl Harbor. Outside of a declared war, however, what authority does the president have? It depends on your interpretation of additional language found within the law. While the law stipulates a declaration of war is required, there are parameters that permit the President to invoke the Alien Enemies Act whenever quote: “any invasion or predatory incursion shall be perpetrated, attempted, or threatened against the territory of the United States,” end quote. 

 

At the risk of belaboring the point, I think it is important to remember how and why this provision might have been included in a law granting the President such singular authority. In 1798, there were no vast communication networks and traveling to the capital took days - sometimes weeks - depending on someone’s origin point. Thus, it was entirely reasonable to think that the president may learn of an expected invasion before a sufficient number of Congressmen could make it back to vote on a declaration of war. A delay could pose serious risk to the country - especially if the suspected alien enemies were close to the capital city. 

 

Thus, when the legislation came across John Adams desk - in the midst of what felt like escalating tensions with a country already at war with Great Britain - Adams signed them into law. As David McCollough highlighted in his biography of Adams, quote: “the United States was at war - declared or not - and there were in fact numbers of enemy agents operating in the country,” end quote. Yet, even John Adams himself considered the Alien and Sedition Acts to be war time powers. Adams’ Vice President, Thomas Jefferson - someone highly supportive of the French - worried extensively about the President’s authority and was concerned the President would misuse the authority to deport the masses. Jefferson’s concerns were unfounded as President Adams never invoked the Alien Enemies Act - despite pushing and encouragement to do so from his Secretary of State Timothy Pickering. 

 

The one law Adams did use during his administration was the Sedition Act – which led to almost instant criticisms. As Presidential Historian Lindsay Chervinsky illustrated in her book about the Adams presidency, quote: “as citizens began to see the implications of the Alien and Sedition Acts through local prosecutions of average citizens, the tide began to turn against the Federalist Party,” end quote. Of the four laws passed in the summer of 1798, only the Alien Enemies Act remains on the books. Both the Sedition Act and Alien Friends Act expired in 1800 and the Naturalization Act was repealed in 1802. Why, you might ask, was it allowed to remain? I couldn’t find any written justification, but my educated guess is that Congress at the time wanted to leave some mechanism in place to protect the country in the event of a declared war and thus left it alone. It was used just one time in the nineteenth century - during the War of 1812 when all British nationals living in the United States were required to report information such as age, length of time in the country, and whether they had already applied for naturalization. 

 

In the twentieth century, presidents invoked the Alien Enemies Act during both World War I and World War II. Woodrow Wilson issued a proclamation on April 7, 1917 - just one day after the United States declared war against Germany - outlining 12 regulations restricting the movement and conduct of what were classified as enemy aliens living in the United States. The proclamation followed the parameters outlined in the Alien Enemies Act which stated that anyone who originates from an enemy country but who has not committed acts against the United States be allowed quote unquote reasonable time to gather their affairs before they vacate the country. During World War I, the U.S. Marshall’s service registered 480,000 German immigrants and arrested 6,300 between the declaration of war in April 1917 and the Armistice at the end of 1918. Those arrested were interned and the United States held over 6,000 Germans and other quote unquote alien enemies in military bases throughout the country in states such as Georgia and Utah. And despite the end of hostilities with the signing of the Armistice on November 11, 1918, arrests continued until February 1919 and the last prisoners were not released until June 30, 1920. 

 

And when Congress declared war in 1942, President Franklin Roosevelt used the Alien Enemies Act to declare Japanese, German, and Italian nationals as alien enemies, requiring residents from each country to register with the United States government and authorized the detention of any alien enemy that was quote “deemed potentially dangerous to the peace and security of the U.S.” end quote. This led to over 31,000 individuals being detained - and this is separate from the Japanese Americans who were interned during the war - whose detention was authorized under a separate legal justification. And like Wilson did during World War I, President Truman continued relying on the powers bestowed upon him by the Alien Enemies Act until 1951 - six years after the end of hostilities. 

 

Truman’s extended use was challenged in a 1948 Supreme Court case Ludecke v. Watkins. The court held that Truman’s decision to rely on the war time authority long after the war had concluded was not a violation of the Alien Enemies Act. Instead, the courts decided that it had no role in second guessing a president’s assessment of when a war ends and when wartime powers expire, calling this a political decision. This set up what is known as the political question doctrine that, according to the Brennan Center for Justice, quote “cautions the courts against addressing issues that fall within Congress and the President’s constitutional duties and that lack judicially manageable standards for resolution,” end quote. This concept was reaffirmed in the 1962 Supreme Court decision in Baker v. Carr. 

 

So where does that leave us today? Why is it that the Alien Enemies Act is being invoked when Congress has yet to declare war against Venezuela? It all lies in the interpretation of the language of the law. As I mentioned earlier, there is text that permits the president to invoke the law whenever an invasion or predatory incursion is expected, regardless of a declaration of war from Congress. There are some who cite this language as giving the President the sole authority in determining when an invasion or incursion is imminent or present. But there are several legal scholars, historians, and political scientists who argue this language should be interpreted literally - as it was during the Adams administration. Critics also highlight that there are other more applicable laws on the books that federal authorities - including the president - could deploy if the aim is to deter illegal immigration and deport anyone in violation of United States law. Finally, those seeking reforms argue the law allows for discrimination against individuals based on nothing more than their country of origin. Two members of Congress have introduced legislation, the Neighbors Not Enemies Act, which would repeal the Alien Enemies Act in its entirety. As of this recording, it has not yet made it out of Congress. 

 

A piece of legislation that was passed before mass communications were available and when travel could take weeks and not hours, the Alien Enemies Act is - much like the Insurrection Act - a product of its time. A law that was passed during an era of high tension and fear of invasion, the Alien Enemies Act no longer accurately reflects the United States in the twenty-first century. It remains to be seen when, or if, it will be amended or repealed. 

 

Thanks, peeps. I will see you next week.