Naturalization Records

Naturalization is the process by which an alien becomes an American citizen. These records can provide a researcher with information such as a person's birth date and location, occupation, immigration year, marital status and spouse information, witnesses' names and addresses, and more.

Before September 27, 1906, any "court of record" (municipal, county, state, or federal) could grant U.S. citizenship.  As a general rule, the National Archives does not have naturalization records created in state or local courts. However, a few indexes cover naturalization records filed in county, state, and local courts and may be available as original records or National Archives microfilm publications.

The U.S. Citizenship and Immigration Services (USCIS, formerly the Immigration and Naturalization Service), 425 I Street NW., Washington, DC 20536, telephone 800-375-5283 has duplicate copies of naturalization petitions created after September 26, 1906 in all Federal, county, and municipal courts. Most inquiries about post-1991 naturalization records must be directed to USCIS as the National Archives generally has such records only through 1991.

Learn more about naturalization records.

From U.S. District Courts (RG 21) in Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin, held in the National Archives, Chicago

Dates indicate overall time span of discrete series of U.S. District Court (Federal) naturalization records in our custody. There are some chronological gaps and incomplete files. Occasionally references to Federal court naturalizations preceding the above dates can be found in early 19th century civil and criminal case records. Besides numerically arranged declarations of intention and petitions, other types of often complex naturalization records exist and may be examined in our Textual Research Room. Consult our staff to arrange a future visit. For Federal court records (including indexes) not yet in our custody, contact the Clerk of the Court for that Federal court.

A separate Soundex Naturalization Index in our custody (reproduced as NARA Microfilm Publication M1285) covers naturalizations filed 1871-1950 in Federal courts in Chicago and 1840-1950 in Federal courts in Danville and Peoria, IL; Hammond, IN; and Madison and Milwaukee, WI. These dates (and other available petition index dates) are reflected above. While the Soundex index also covers non-Federal municipal and county courts in parts of Illinois, Indiana, Iowa, and Wisconsin, we do not have custody of non-Federal court records. For possible assistance with non-Federal court records, contact the appropriate non-Federal court clerk or State archives. Refer to books such as Guide to Naturalization Records of the United States by Christina Schaefer, County Courthouse Book by Elizabeth Petty Bentley, or The Handybook for Genealogists for information about county court records and repositories having custody of them.

Many naturalization series in the National Archives have been digitized by our digitization partners and are available online.