The citizenship and immigration service (USCIS) is a federal agency that decides citizenship, green card, and other applications of non-asylum seekers. As an applicant, you get the option to submit your application online with some types of forms. In other cases, you have to submit a paper application.
After you submit your application, the federal agency interviews you to determine your eligibility. This process takes place at a field office. Such offices are present in many States and also U.S. territories. For overseas applicants, the USCIS site has a tool for searching the nearest location. If you’re inside the U.S., you can search the nearest location by providing your zip code online. The agency will also provide you this information in the appointment notification.