Dear Mr. Mazikowski,
Thank you for posting your request on History Hub!
We suggest that you review these Genealogy: Passenger Arrival List Research Tips to learn how to locate immigration information for your grandparents. There are numerous ways that individuals could enter the United States from Europe such as on a ship that arrived at various coastal ports or over land from Canada, etc. Ship passenger arrival lists were a requirement beginning in 1820, but that does not guarantee that person was recorded or that the list still exists. Many of the passenger lists have been digitized and are name-searchable online using Ancestry.com and FamilySearch.org. There may be a fee for using Ancestry. Instead, you may wish to contact your local library. Many library systems subscribe to these sites, making them free for patrons.
Prior to September 27, 1906, any "court of record" (municipal, county, state, or Federal) could grant United States citizenship. Often petitioners went to the court most geographically convenient for them. As a general rule, the National Archives does not have naturalization records created in state or local courts. However, a few indexes and records have been donated to the National Archives from counties, states, and local courts. We suggest that you contact the National Archives facility serving the state in which the petitioner resided to determine if records from lower courts are available. If the records are not available, we suggest that you request a search for the naturalization records from the State Archives or County Historical Societies.
Beginning on September 27, 1906, the responsibility for naturalization proceedings was transferred to the Federal courts. If a naturalization took place in a Federal court, naturalization indexes, declarations of intention (with any accompanying certificates of arrival), and petitions for naturalization will usually be in the custody of the National Archives facility serving the state in which the Federal court is located.
Unfortunately, no central index exists. To ensure a successful request, please 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).
Certificates of citizenship were issued by the Federal courts until October 1991 when INS took over responsibility for naturalization proceedings. 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 since September 27, 1906 and may be requested through the USCIS Genealogy Program.
We hope this is helpful. Best of luck with your family research!
NARA has passenger arrival lists beginning in 1820 for most ports (it has a few earlier records for the port of Philadelphia). These records are indexed and available on Ancestry.com and some dates for some ports are available on familysearch.org. There are gaps in some of the earlier records due to damage to the pages when stored at the various ports. If you want to share the names, approximate birth dates or ages, and country of origin, someone here will help you find the records.