The Naturalization Act of 1790, enacted by the First US Congress, was the first naturalization law passed in the United States after the ratification of the Constitution in 1787.

“An act to establish an uniform Rule of Naturalization,” United States Congress, March 26, 1790

Be it enacted by the Senate and House of Representatives of the United States of America, in Congress assembled, That any Alien being a free white person, who shall have resided within the limits and under the jurisdiction of the United States for the term of two years, may be admitted to become a citizen thereof on application to any common law Court of record in any one of the States wherein he shall have resided for the term of one year at least, and making proof to the satisfaction of such Court that he is a person of good character, and taking the oath or affirmation prescribed by law to support the Constitution of the United States, which Oath or Affirmation such Court shall administer, and the Clerk of such Court shall record such Application, and the proceedings thereon; and thereupon such person shall be considered as a Citizen of the United States. And the children of such person so naturalized, dwelling within the United States, being under the age of twenty one years at the time of such naturalization, shall also be considered as citizens of the United States. And the children of citizens of the United States that may be born beyond Sea, or out of the limits of the United States, shall be considered as natural born Citizens: Provided, that the right of citizenship shall not descend to persons whose fathers have never been resident in the United States: Provided also, that no person heretofore proscribed by any States, shall be admitted a citizen as aforesaid, except by an Act of the Legislature of the State in which such person was proscribed.