History and Genealogy
Immigration and nationality records changed over time. For this reason there is no one set of instructions to guide family history research. What records exist and how to find them depend entirely on when the immigrant arrived and if, when, or how they became a United States citizen.
Arrived before 1924
Arrival 1924 to ca. 1944
Arrival before August 1940 and not naturalized by August 1940
Arrival between March 31, 1944 and May 1, 1951
Arrival after May 1, 1951
1790 to September 26, 1906
September 27, 1906 to March 31, 1956
Since April 1, 1956
U.S. Citizenship and Immigration Services (USCIS) began operations on March 1, 2003. During the preceding century, the Immigration and Naturalization Service (INS) oversaw federal immigration and naturalization policy. Thus, students and scholars interested in the origins of USCIS and the policies it administers, as well as those studying the immigration policies now carried out by Customs and Border Patrol (CBP) and Immigration and Customs Enforcement (ICE), often begin their historical research in the records of INS. This guide will equip you with the knowledge necessary to identify and request historical INS files from both the National Archives and, for more recent files, USCIS.
For more than a century, the INS and its predecessor agencies generated numerous types of records and organized and indexed these records in a multitude of ways. Generally, INS records can be divided into two categories:
If you are interested in researching a specific immigrant’s experiences, see our Guide to the Records of Individual Immigrants. If you are interested in researching the history of federal immigration agencies such as INS and the Border Patrol, or any aspect of twentieth century immigration and nationality policy, you should begin with the subject research guide.
Research with INS’ historical files requires time, patience, and sometimes familiarity with unclear archival language. Students, and even experienced scholars who approach the records without proper preparation can quickly become frustrated. For example, archivists can seldom retrieve records on a given topic. Instead they need a specific Record Group (RG), entry, and file numbers.
The subject research guide will equip you with the knowledge necessary to identify and request historical INS files from both the National Archives and USCIS.
Today, most INS subject, policy, administrative, and correspondence files dated before 1956 are part of RG 85, Records of the Immigration and Naturalization Service (INS), at the National Archives in Washington, D.C. Within RG 85 the files are divided into separate entries depending on the date and to some extent the topic of the file.
Our research guide currently includes information about INS’s four main records series:
Updates to the research guide will cover additional records including records related to Chinese Exclusion Act enforcement. Please send us a message if you would like to receive notices about updates to the guide.
Last Reviewed/Updated: 09/08/2015