• U.S. Passport -- accepted for travel by air, land and sea.
- How to Get Your First U.S. Passport
- How to Rush a U.S. Passport
- How to Check the Status of a U.S. Passport Application
• U.S. Passport Card –- valid for travel by land and sea. The PASS, or passport card, or passport substitute,is a cheap alternative to a passport if you know you're only going to be traveling between the US and Canada or Mexico.
• Enhanced Driver’s License (EDL) –- a few states and Canadian provinces are issuing this "high tech" driver’s license as an identification document for cross-border travel into the U.S. by land or sea.
• Trusted Traveler Program Cards –- NEXUS, SENTRI or FAST enrollment cards are probably not of interest to backpackers: they speed entry into the US and are issued only to pre-approved, low-risk travelers. The cards are valid for use at land or sea; the NEXUS card can be used in airports with a NEXUS kiosk. The PASS card is easier, and a passport is better.
And then there are special groups:• Special Groups –- Minors and groups of children, Native Americans, people on "Closed Loop" cruises, U.S. Lawful Permanent Residents, U.S. Military, Merchant Mariners, Ferries and Small Boats, and Boaters all have their own rules.