Naturalization records document the granting of US citizenship through judicial proceedings, and INS naturalization records duplicate those found in naturalization courts throughout the country. INS also maintains a variety of citizenship records , among them records relating to derivative citizenship, resumed or restored US citizenship, or loss of US citizenship. To locate pre-1906 naturalization records, or any naturalization records filed with courts, start your research at the National Archives .
Occasional files contain additional documents or correspondence.
INS maintains an index to the C-Files, and can retrieve individual records based on name, date of birth, and place of birth. D.C. For naturalization records after 1956, Freedom of Information requests should be sent to the appropriate INS District Office. An index to naturalizations of soldiers during World War I may be found at the National Archives.