A little-known program of the U.S. Citizenship and Immigration Services (USCIS) provides genealogy information that may be difficult or impossible to obtain elsewhere. The records include naturalization files, visa applications, and citizenship tests, and may reveal family secrets and mysteries. In addition to relatives, historians or researchers can also request files.
Under the USCIS Genealogy Program, which started in 2008, requests are usually completed within 90 days. The government will run a search of the name, as long as the person is deceased. If there are records available, the government charges additional fees for the files. The fee for a record copy from microfilm identified as (M) is $20 per request. The fee for a copy of a hard copy file identified as (HC) is $35 per request. More information about the fees associated with each file series may be found at http://www.uscis.gov/history-and-genealogy/genealogy/historical-records-series-available-genealogy-program.
If the immigrant applied for American citizenship, the details are also included in these files. For anyone of Japanese, German, or Italian origin who lived in the United States during World War II, the documents often include FBI reports about the person's activities, including friends, family, and political activities.
For more information about the program, check out http://www.uscis.gov/genealogy.