United States: know before you go

Entry rules turn on your passport. Citizens of Visa Waiver Program countries can visit for tourism or business for up to 90 days without a visa, as long as they hold an approved ESTA and an electronic passport. Everyone else needs a visa from a US embassy or consulate before traveling. The airline checks your documents at check-in, and a Customs and Border Protection officer makes the final admission decision when you land.

Most international flights land at one of the major gateway airports, including New York JFK, Newark, Chicago O'Hare, Los Angeles, San Francisco, Miami, and Atlanta. You clear immigration and customs at your first US airport of arrival, even when you are connecting onward. Plan for that layover to take time: collect your bags, clear customs, recheck them, and go through security again. There is no exit immigration when you leave, so your departure is handled by the airline at check-in.

The United States is large, and no single pass covers it the way a Eurail pass covers Europe. Amtrak's USA Rail Pass is the closest thing, and it makes sense for a trip that strings together several cities on one or two long-distance routes. For most trips, though, you will mix domestic flights, trains, buses, and a rental car. Flights between major cities are frequent, but the country is vast, and a cross-country flight eats most of a day once you add airport time. Long-distance buses from companies like Greyhound and FlixBus fill the gaps where trains are slow or infrequent. Check a route map before committing, because a train between two cities can take a full day where a flight takes a couple of hours.

The dollar is the only currency, and cards rule. Visa and Mastercard are accepted nearly everywhere, while American Express and Discover are less universal. Carry a small amount of cash for tips, street food, and small shops. Tipping is expected rather than optional: 15 to 20 percent at sit-down restaurants and bars, a dollar or two per drink, and a few dollars per bag for porters. Sales tax is not included in the price on a menu or shelf, so the total at the register will be higher than the sticker, from zero in a few states to 10 percent or more in some cities. Hotel taxes, also called occupancy taxes, vary by city and can add a noticeable amount to your room rate.

The United States is broadly safe for visitors, and violent crime is rare in the tourist areas most travelers visit. The bigger risks are practical: extreme weather, long distances, and unfamiliar roads. Atlantic and Gulf coast states face hurricanes from summer into fall, the central states get tornadoes in spring, the West has wildfire season in summer and fall, and earthquakes are a low-probability but real risk in California and the Pacific Northwest. In any emergency, call 911. Petty theft happens in crowded tourist zones, so keep a hand on your bag on transit and do not leave valuables visible in a parked car.

Tap water is safe to drink in most of the country and in every major city. The United States has no universal public healthcare, and visitors pay for treatment, so travel insurance with medical coverage is worth buying before you leave. Pharmacies are everywhere: CVS, Walgreens, and Rite Aid are the big national chains, many open late or 24 hours, and they sell over-the-counter medicine without a prescription. For anything serious, hospital emergency rooms must treat you, but the bill will follow.

Mobile service is excellent in cities and along highways, and free Wi-Fi is standard in hotels, cafes, and airports. International visitors can roam on their home plan, buy a prepaid SIM at the airport or a carrier store, or install an eSIM before landing. The three big networks are Verizon, AT&T, and T-Mobile. Coverage thins out in national parks and remote desert or mountain areas, so download maps and tickets before you go.

Americans are generally informal and direct, and they value personal space: an arm's length is normal in conversation, and small talk with strangers is common in lines and stores. Queueing is taken seriously, and cutting a line will draw real annoyance. Tipping is the custom visitors most often get wrong, so treat the 15 to 20 percent restaurant tip as part of the price. Smoking is banned indoors in most states, and the legal drinking age is 21 everywhere, so carry ID if you want to buy alcohol and expect to be carded.

English is the de facto national language and the language you will use everywhere, but the United States has no official language at the federal level. Spanish is widely spoken, especially in Miami, Los Angeles, and the Southwest, and you will hear it on signs and in stores in many cities. Hawaii has English and Hawaiian as official state languages, and communities across the country speak dozens of other languages. Street signs, menus, and transit announcements are in English, and English proficiency among service staff is high.

The Americans with Disabilities Act requires public places, transit systems, hotels, and restaurants to be accessible, so curb cuts, elevators, accessible rooms, and wheelchair-friendly transit are common in cities. Older buildings and some historic areas can be uneven, and coverage is thinner in small towns. National parks and major attractions generally provide accessible facilities, but call ahead for anything specific. Service animals are permitted in public places, while emotional support animals are not automatically granted the same access.

Federal holidays close government offices, banks, and post offices, and schools take many of them off. Retail, restaurants, and attractions mostly stay open, sometimes with reduced hours. The big travel days are the ones to plan around: the Wednesday before and Sunday after Thanksgiving, and the Christmas to New Year period, when airports are packed and prices peak. On July 4 many cities hold fireworks and some businesses close early. A few states and cities observe Columbus Day under the name Indigenous Peoples' Day.

Book early for the things that sell out: popular national parks, big-city theater and sports tickets, and hotel rooms around major events. Several national parks use timed-entry reservations or advance permits during their busiest months, and a few require them for peak-season entry. For everything else, buying flights and intercity train tickets a few weeks ahead is enough. In the big cities, restaurants take reservations and the hardest tables go weeks out, so book those the moment your dates are set.