Dear Ms. Iovenitti,
Thank you for posting your request on History Hub!
In general, naturalization was a two-step process that took a minimum of five years. After residing in the United States for two years, an alien could file a "declaration of intention" ("first papers") to become a citizen. After three additional years, the alien could "petition for naturalization" (”second papers”). After the petition was granted, a certificate of citizenship was issued to the alien. These two steps did not have to take place in the same court.
Beginning September 27, 1906, the responsibility for naturalization proceedings was transferred to the Federal courts. Naturalization indexes, declarations of intention (with any accompanying certificates of arrival), and petitions for naturalization will usually be in the National Archives facility serving the state in which the Federal court is located. No central index exists. To ensure a successful request with the National Archives, your email should include: the name of petitioner (including known variants); date of birth; approximate date of entry to the US; approximate date of naturalization; where the individual was residing at the time of naturalization (city/county/state); and country of origin.
In most cases, the National Archives will not have a copy of the certificate of citizenship. Two copies of the certificate were created – one given to the petitioner as proof of citizenship, and one forwarded to the Immigration and Naturalization Service (INS).
All INS records are now overseen by the US Citizenship and Immigration Services (USCIS). USCIS maintains duplicate copies of court records (including the certificate of citizenship) created from September 27, 1906 through March 31, 1956 within Certificate Files (C-Files). C-Files may be requested through the USCIS Genealogy Program.
We hope this is helpful. Best of luck with your family research!