On this form the immigrant listed the port name, date and ship of arrival. Copies of this form were sent to the port of entry and checked by a clerk, who located the immigrant's passenger list. If a corresponding record was found, the INS issued a certificate of arrival and sent it to the naturalization court. Certificates of arrival were first issued under the Basic Naturalization Act of 1906, which went into effect on 27 September 1906. These certificates are generally included in a naturalization records file.