1790 Naturalization Act (An act to establish an uniform rule of naturalization)
Sess. II, Chap. 3; 1 stat 103.
1st Congress; March 26, 1790.
This article of legislation allowed an individual to apply for citizenship if they were a free white person, being of good character, and living in the United States for two years. Upon receiving the courts approval they took an oath of allegiance which was recorded. The individual's citizenship was also extended to any children under the age of 21, regardless of their birthplace. If the applicant had never been a U.S. resident the application was disregarded.
(Summary by Shelby Englund)
Background History of the United States Naturalization Process - This site provides a collective overview of the history of naturalization starting with the 1790 law.
Naturalization and Citizenship: Nature and Scope of Congress' Power - This site provides an annotated version of the U.S. Constitution, here focusing on naturalization law.
Naturalization Records (from the National Archives) - This site is helpful to show the transitions of naturalization law starting in 1790.