The Federalists, now controlling both the Senate and the House of Representatives, argued that the possibility of open war with France and the publicized attempts at espionage by French agents in the United States required Congress to take drastic action to guard against breaches in national security. To this end Congress passed a series of four measures, known collectively as the Alien and Sedition Acts. John Adams signed the Alien and Sedition Acts during June and July 1798, but it was only with the gravest misgivings that he did so, for the acts asserted the power of the central government to an unprecedented extent.

The first, and least controversial, act was the Alien Enemies Act. This act defined the procedure by which US authorities could determine whether a citizen of an enemy nation posed a threat to national security during wartime. If found guilty under the outlined procedures, the guilty party would be deported or detained. The Alien Enemies Act was not called into use until the War of 1812.

The second Act, the Alien Friends Act, was effective during peacetime, and allowed the president to deport any citizen of any foreign nation who he decided posed a threat to the nation while inside its borders. The law allowed the president to expel citizens without proof of guilt, claiming that spies would be adept at destroying evidence and able to easily fool many authorities. The statute was only enforceable until June 25, 1800, before the end of Adams' term and the 1800 congressional elections.

The Third act was the Naturalization Act. The Naturalization Act revised the procedures by which an immigrant could become a citizen of the United States. Rather than having to establish residency in the US for five years before becoming eligible to become a citizen, the Naturalization Act increased the residency requirement to fourteen years.

The final, and most controversial, of the Alien and Sedition Acts, was the Sedition Act. It forbade any individual or group to oppose "any measure or measures of the United States." Under the Sedition Act, it was illegal to speak, write, or print any statement about the president which brought him, in the wording of the act, "into contempt or disrepute." The Sedition Act was set to expire in 1801. Four of the five major Republican newspapers were charged with sedition just before the presidential election of 1800, and several foreign born journalists were threatened with expulsion. The Attorney General charged seventeen people with sedition, and ten were convicted.

The strongest reaction to the Alien and Sedition Acts flared up in the South. In November and December 1798, shortly after the passage of the acts, both Kentucky and Virginia endorsed manifestos on states' rights, written anonymously by Thomas Jefferson and James Madison, respectively. These resolutions stated that state legislatures maintained the power of interposition, which allowed them to judge the constitutionality of acts of Congress. In 1799, Kentucky passed a resolution that declared that states could nullify objectionable federal laws.

Popular pages: The First Years of the Union (1797-1809)