The United States Congress
The Naturalization Act extended the duration of residence required for aliens to become citizens from 5 years to 14 years. Enacted June 18, 1798, with no expiration date, it was repealed in 1802.
United States citizens and immigrants
To increase the amount of time necessary for immigrants to become naturalized citizens in the United States
Although this law was passed under the guise of protecting national security, many believe it was really intended to decrease the number of voters who disagreed with the Federalist political party. At the time, most immigrants (namely Irish and French) supported the Democratic-Republicans, the political opponents of the Federalists.
SECTION I. Be it enacted… That no alien shall be admitted to become a citizen of the United States, or of any state, unless in the manner prescribed by the act, instituted "An act to establish an uniform rule of naturalization"… he shall have declared his intention to become a citizen of the United States, five years, at least, before his admission, and shall, at the time of his application to be admitted, declare and prove, to the satisfaction of the court having jurisdiction in the case, that he has resided within the United States fourteen years, at least, and within the state or territory where, or for which such court is at the time held, five years, at least, besides conforming to the other declarations, renunciations and proofs, by the said act required, any thing therein to the contrary hereof notwithstanding: And provided also, that no alien, who shall be a native, citizen, denizen or subject of any nation or state with whom the United States shall be at war, at the time of his application, shall be then admitted to become a citizen of the United States.