Alien and Sedition Acts, in United States history, a series of four laws passed by Congress in 1798 during the Presidency of John Adams. At that time, war threatened between France and the United States. The acts were passed ostensibly as security measures against French agents and sympathizers in the United States. Actually, the laws were designed by the Federalist-controlled Congress to suppress criticism of the government by the opposition Republican (forerunner of the Democratic) party.

The acts were aimed particularly at a group of foreign-born (mainly French) editors and pamphleteers, sympathetic to the Republican cause, who were heaping abuse on the administration. The Federalists hoped that the laws would weaken the political strength of the Republicans and their leader, Vice President Thomas Jefferson.

The laws were:

  • The Naturalization Act, extending the residence requirement for United States citizenship from 5 to 14 years.
  • The Alien Act, empowering the President to expel any alien whom he believed dangerous to the nation's security.
  • The Alien Enemies Act, authorizing the President to order from the country all aliens from a nation warring against the United States.
  • The Sedition Act, making it a crime, punishable by fine and imprisonment, to libel the President, Congress, or the government.

Although the Alien Act was never applied, the threat of enforcement caused many French residents to leave the United States. A number of persons were prosecuted under the Sedition Act, 10 eventually being convicted in the courts. The Naturalization Act worked hardships on aliens of all nationalities.

Much resentment was aroused. Republicans assailed the acts as despotic and unconstitutional. The legislatures of Kentucky and Virginia passed resolutions denouncing the Alien and Sedition Acts and calling upon other states to nullify them. Indignation stirred by these acts contributed to the defeat of the Federalists and the election of Jefferson to the Presidency in 1800.

The Alien Act expired in 1800 and was not renewed. In 1801 the Sedition Act also expired. All those convicted under this act were pardoned by President Jefferson, who had considered it unconstitutional. The uralization Act was repealed in 1802. The Alien Enemies Act never went into effect because its operation was contingent upon a declaration of war.