Immigration

The U.S. Department of Homeland Security has oversight of the U.S. Citizenship and Immigration Service (USCIS) whose responsibility is the administration of immigration and naturalization adjudication functions and establishing immigration services policies and priorities. USCIS has many offices throughout the United States including one in Memphis, Tennessee. All immigration matters should be directed to the USCIS office in Memphis.

USCIS Memphis Website

USCIS Customer Service 1 (800) 375-5283

http://uscis.gov/graphics/fieldoffices/memphis/
aboutus.htm#anchor1700968

Travel

The US Department of State has an entire section on travel and living abroad.  The information on this site includes travel warnings and public announcements as well as crisis awareness and preparedness advice.
The Transportation Security Administration (TSA) is responsible for security for all modes of transportation. The TSA web site has information for travelers regarding traveler's do's and don'ts and advice on traveling safely.