U.S. Citizenship and Immigration Services, General Information
https://www.uscis.gov

U.S. Citizenship and Immigration Services, I-9 Central
800-375-5283
https://www.uscis.gov/i-9-central

U.S. Citizenship and Immigration Services, I-765 Application for Employment Authorization
800-375-5283
https://www.uscis.gov/i-765