Dear Mr. Romero,
Thank you for posting your request on History Hub!
The U.S. Citizenship and Immigration Services (USCIS, formerly the Immigration and Naturalization Service) can issue replacement copies of certificates of citizenship and verify citizenship. Please download and complete their request form to send by mail or online.
Also, all immigrants admitted since May 1, 1951 should be entirely documented in an Alien File (A-File). The USCIS manifest arrivals and A-Files are available through the USCIS Freedom of Information Act Program (FOIA): https://www.uscis.gov/g-639. The form must be submitted to the USCIS address listed under the “Where to File” tab.
We hope this information is helpful.