Passports issued after October 26, 2005 need digital photographs embedded on them, and passports issued after October 26, 2006 must be e-passports, which have a chip embedded with the user's information. Some countries, e.g. France, did not have e-passports available at that date, meaning that citizens from these countries with newer passports but not e-passport have to obtain a tourist visa, which can be a cumbersome, costly and time-consuming process. If you have a non e-passport issued after October 26, 2006 and you are from a visa waiver country, try having your government exchange it for an e-passport, explaining that you wish to travel to the US.
The countries under the Visa waiver program are Andorra, Austria, Australia, Belgium, Brunei, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Liechtenstein, Luxembourg, Monaco, the Netherlands, New Zealand, Norway, Portugal, San Marino, Singapore, Slovenia, Spain, Sweden, Switzerland, United Kingdom.
Visa waiver visitors should note that returning the green card stapled to their passport on entry is their responsibility. If it is not returned at the end of your visit, you might be deemed to have stayed in the US and then be refused entry in future. Airline or border staff will typically take this card from you on departure, but check and insist on it, and if you leave the country with it in your possession, contact US officials about how to return it and update your departure record as soon as possible. You will need to present a substantial amount of evidence that you in fact left the country before the waiver expired, such as foreign payslips or credit card bills for the relevant dates; it is much easier to return the slip when boarding for departure.
For the rest of the world (including Mexicans not living in the border), the visa application process is onerous, expensive, and slow. The application fee is US$100 (not refundable even if your application is rejected). Face-to-face interviews (where the official needs to be convinced that you are not a "potential immigrant") at the nearest US embassy or consulate are required for many nationalities, and waits for interview slots and visa processing can add up to several months.
The best advice for travelers today, from any country, is not to assume, but to check on documentation requirements with the United States State Department or with your nearest United States consulate. In addition, if coming to the country by car, be sure to have documents including car insurance, rental agreements, drivers license, etc., before trying to enter the US, as the process has become more strict in the last few years.
All visitors go through a short interview at immigration, where the official tries to determine if the traveler's stated purpose of visit is valid. Be prepared to show proof. For example if you are on a business visit, it is advisable to have an invitation letter from the company you are visiting, and a return ticket. If you are a tourist, you'll probably need to show proof of hotel bookings, etc. Whether they choose to give you a hard time or let you in without much notice seems to depend on your citizenship, ethnicity, and general appearance (shabby clothing and long hair may elicit greater attention than casual business attire, for instance). Once they decide to let you in, you are fingerprinted and a digital photograph is taken. As in most countries, it is also important to note that customs officials are required by law to treat any comments about bombs, terrorism, or other security issues extremely seriously; unless you are looking for an excuse to spend an hour or so being interrogated do not make even the most flippant remark about any of these subjects within earshot of any customs or other security official.
For non-residents, your entry forms will need to state the street address of the location where you will be staying. The name of your hotel, hostel, university etc may not be sufficient; you must provide the street address including the street number. Look this up before leaving home. If staying in multiple locations, provide the address where you will be spending the first night of your stay. This also means it is unwise to arrive in the United States without planned accommodation for your first night.
The Department of Homeland Security has now named the program of additional security measures US-VISIT and is now piloting a measure where you need to leave your fingerprint and photograph at a kiosk even while leaving. Currently, this is applicable at 12 airports and 2 seaports. Check the list, as most of the important ports of entry are covered.
Travelers from other continents may not bring meat or raw fruit or vegetables into the U.S., but may bring cooked nonmeats, such as bread. See APHIS for details. You will be given a sheet of paper with checkboxes for products such as food. Answering "yes" to any of these checkboxes may result in a search of your luggage and a longer interrogation about your motive for travelling in the US, even though the product is legal to import.By plane
Most visitors from outside Canada and Mexico arrive in the United States by plane. While even medium sized inland cities such as, for example, Pittsburgh, Pennsylvania, have an international airport there are limited flights to most of these airports and most travelers find themselves entering the US at one of the major entry points along the coasts. The three primary entry points to the country are:
Note that the United States does not recognize the concept of international transit. You must have a valid visa to enter the United States, even if you are continuing on a flight to different country. It is advisable to avoid transiting through the U.S. if you don't have a visa. Further, when booking flights to the US note that you will be required to clear customs and immigration at your first US stop, not at your final destination, even if you have an onward flight. Allow at least 2 hours of stopover (ideally more than 3) at your first US stop.By car
As to roads from Canada and Mexico, they are too numerous to mention and travelers should consult Google Maps or any other online mapping service. You will be able to get detailed itineraries from wherever you are to wherever you wish to go.By boat
Entering the US by sea, other than on a registered cruise ship, may be difficult. The most common entry points for private boats are Los Angeles and the surrounding area, Florida, and the Eastern coastal states.
Some passenger ferries exist between Canada and the US, notable from the Atlantic Provinces to New England, and from Victoria, British Columbia to Seattle.By train
Amtrak offers international service from Vancouver, Toronto, and Montreal into the US.