In 1798, President John Adams signed the Alien and Sedition Acts, which were passed by the Federalist-dominated 5th United States Congress. They made it harder for an immigrant to become a citizen (Naturalization Act), allowed the president to imprison and deport non-citizens who were known as dangerous ("An Act Concerning Aliens", also known as the "Alien Friends Act" of 1798) or who were from a hostile nation ("Alien Enemy Act" of 1798), and criminalized making 'false statements' critical of the federal government ("Sedition Act" of 1798). The "Alien Friends Act" expired two years after its passage, and the "Sedition Act" expired on 3 March 1801, while the "Naturalization Act" and "Alien Enemies Act" had no expiration clause.

The Federalists argued that the bills strengthened national security during the Quasi-War, an undeclared naval war with France from 1798 to 1800. Critics argued that they were primarily an attempt to suppress voters who disagreed with the Federalist party and its teachings, and violated the right of freedom of speech in the First Amendment to the U.S. Constitution.The Naturalization Act increased the residency requirement for American citizenship from five to fourteen years. At the time, the majority of immigrants supported Thomas Jefferson and the Democratic-Republicans, the political opponents of the Federalists. The Alien Friends Act allowed the president to imprison or deport aliens considered "dangerous to the peace and safety of the United States" at any time, while the Alien Enemies Act authorized the president to do the same to any male citizen of a hostile nation above the age of fourteen during times of war. Lastly, the controversial Sedition Act restricted speech that was critical of the federal government. Under the Sedition Act, the Federalists allowed people who were accused of violating the sedition laws to use truth as a defense. The Sedition Act resulted in the prosecution and conviction of many Jeffersonian newspaper owners who disagreed with the government.The acts were denounced by Democratic-Republicans and ultimately helped them to victory in the 1800 election, when Thomas Jefferson defeated the incumbent, President Adams. The Sedition Act and the Alien Friends Act were allowed to expire in 1800 and 1801, respectively. The Alien Enemies Act, however, remains in effect as Chapter 3; Sections 21–24 of Title 50 of the United States Code. It was used by the government to identify and imprison allegedly "dangerous enemy" aliens from Germany, Japan, and Italy in World War II. (This was separate from the Japanese internment camps used to remove people of Japanese descent from the West Coast.) After the war they were deported to their home countries. In 1948 the Supreme Court determined that presidential powers under the acts continued after cessation of hostilities until there was a peace treaty with the hostile nation. The revised Alien Enemies Act remains in effect today.