Staple Foods
Being a country of immigrants, there are no staple foods that exist across the U.S.A.. Many of the immigrants and American Indians, however have staples, from rice for many Asian immigrants to corn tortillas for Hispanic immigrants.
Regional Variations, Specialties, & Unique Dishes
BBQ: popular everywhere, but centered in Memphis, Tennessee; Kansas City, Missouri; & Texas
California: fresh ingredients and Asian foods dominate here
Chicago: famous hot dogs, Italian sausage, and deep dish pizza
Hawai'i: focused on pork products and a local root called taro, today Asian immigrants have altered the food even more
Louisiana: Cajun cooking (essentially French influenced with more rice and seafood) rules here and includes po'boys, jambalaya, and gumbo to name just a couple
Midwest: known for their meats, cheeses, and dishes based on Germany, Irish, and Polish foods
New England: on the sea, their food is based on multiple fish and shellfish
New York City: well known for their Kosher delis, pizza, hot dogs, and ethnic foods
Philadelphia: cheese steaks rule here; traditionally served with beef, fried onions, and cheese whiz on Italian bread
South-Western: similar to Mexican food, but typically with more meat and more inventive as each chef tries to create his own dish
Southern: also known as comfort food, some of the favorites include cornbread, pecan pie, and fried chicken
Tex-Mex: a name given to foods that are influenced by Texas and Mexico; popular in Texas, the southwest, and California
Dining Etiquette
Dining in the U.S.A. varies from highly sophisticated to extremely informal and, fortunately, usually falls closer to the informal side of the spectrum. With a fast food culture growing and eating on the run popular, eating as you walk or in the company of others isn't considered rude. While eating in quick service restaurants essentially means there are no true dining rules.
In more formal settings, place your napkin on your lap, wait to eat until everyone is served, and use your silverware (cutlery) from the outside in. These rules also apply if you're a guest at anyone's house, although there may be appetizers you can snack on without waiting, plus some people are extremely informal so just follow your host's lead.
If dining as a guest at someone's house, always arrive on time, bring a small gift (or a dish if asked), and follow the host's traditions; this could mean a pre-meal prayer or toasts, which are typically limited only to the host, but if others join in, all are welcome to participate. It is also not considered rude to turn down a dish that does not appeal to you, however do so quietly and ask for another dish instead. Once you have food on your plate, it is considered polite to finish everything you have taken; leaving food can implied that the food was not satisfactory, unless of course, you're on your third helping.
If dining out, who pays for dinner varies greatly based upon the company. For business dinners the inviter typically pays the entire bill. For a more informal or friendly meal there are no set rules. Although the host may pay the entire bill, you should offer to contribute money and, many times, the offer will be accepted or the bill will be divided evenly among all guests.
When eating out at a sit-down restaurant a tip of between 12-20% is expected (depending on the quality of the service). Unlike in Europe, waiters and waitresses get low pay and are reliant on tips as a supplement to their income. In bars a tip of $1 per order is standard.
Celebrations & Events
A few American holidays and celebrations include specific foods. The holiday most associated with a particular food is Thanksgiving (third Thursday in November), which serves turkey, stuffing, mashed potatoes, and yams along with numerous other side dishes and desserts, most commonly pies.
A couple holidays are notorious for being outdoor festivals and therefore grilling meats, including hamburgers, hot dogs, and various sausages (Polish kielbasa and German bratwurst among others) are common along with much junk food like chips and desserts. Independence Day (July 4), Memorial Day (last Monday in May), and Labor Day (first Monday in September) are the best outdoor eating holidays in the United States.
Numerous other holidays have foods associated with them. Halloween (October 31) is filled with candy as is Valentine's Day (February 14). Birthdays, anniversaries, and other celebrations often include cake and perhaps ice cream. Some foreign holidays are also celebrated with the foods and drinks from those countries; St. Patrick's Day (March 17) is celebrated with beer, corned beef, and cabbage while Cinco de Mayo (May 5) is met with much Mexican food.
Drinks
Americans drink just about every type of alcoholic and non-alcoholic drink depending on personal taste. Many sodas (or colas or pops) are from the United States with Pepsi and Coca-Cola being the most well-known and popular. However, juices, water, and other non-alcoholic drinks are also popular and easily accessible.
Wine, beer, and hard liquors are all popular. Perhaps the most authentically American drink is bourbon, a type of whiskey. Depending on your location in the United States, differing drinks are more or less popular, including vodka, whiskey, tequila, and rum. Beer is still the most popular alcoholic drink though and wine is growing in popularity, especially as the reputation and awareness of California wines expands.
The tap water is safe to drink in the United States. However, many people may have trouble adjusting to the local tap water, as it will most certainly be different from what your system is used to if you are not from North America.