The United States of America is a massive country, with much to see and do. Accordingly, it is an exciting destination for travel and tourism. Recent changes in international travel and guidelines by the Transportation Security Administration, however, have left some travelers curious about what is needed when they travel. Whether you are a guest or a resident, the guidelines remain relatively simple.

Traveling as a Resident

As a citizen of the United States, you are encouraged to travel with identification. A form of photo ID will likely be necessary for checking into hotels, writing checks or traveler's checks, or verifying a credit card. Acceptable forms of photo IDinclude any state ID card or driver's license, the new enhanced driver's licenses, a military ID or your passport. The Social Security Administration encourages you not to carry your Social Security Card.

Traveling as a Guest of the United States

A foreign national traveling in the United States requires more documents than a resident. You should have your passport with you at all times. Losing a passport can be a massive inconvenience, so consider investing in a hidden traveler's wallet for carrying important documents. If you plan to drive, you may also require an international driver's license, depending on your nation of origin. You should always have your visitor's visa paperwork handy as well.

Traveling as a Legal Alien

As a green-carded resident of the United States, that is, a foreign citizen who resides in the U.S., you must always have your green card with you as well as your regular photo ID. In some cases, your green card functions the same way as a driver's license or other photo ID, but you should always have both with you at all times as you travel in the United States, to avoid any potential confusion. You are not required to carry a passport to travel inside the country.