Since America is so large, drinking customs vary greatly across cities and regions. It really depends on where you go!
In many rural and suburban areas, you'll find your alcoholic drinks are mostly found in restaurants and people are more accustomed to having drinks at their home. In urban settings, it's likely you’ll find a range of bars and nightclubs that serve any type of drink you can think of. In the party cities of America, like Miami, NYC and Chicago, drinking establishments will be more varied, and physically closer together, making barhopping much more popular. In places like this, you’re likely to see a diversity of local “shot and a beer” bars to more upscale “Martini bars”, and everything in between.
Beer is one of the default choices for anyone drinking in the USA. The beer scene is flourishing across the country, and there are plenty of breweries you can visit, and a great craft beer scene. Microbreweries have also been getting quite popular, making different types of beers in much smaller quantities than the major breweries. These are most often distributed regionally.
Wine is labelled by the grape (Merlot, Cabernet Sauvignon, Riesling...) in the USA. Wine lists are usually categorised by red, white, rose (or pink), but it’s customary to indicate what type of red or white or pink you want. The most famous American wine region is Napa Valley in California, although there are also a number of other regions within the state that produce great wine. Other wine-producing regions in the US include Oregon’s Willamette Valley, the state of Washington, the state of Michigan, Colorado’s Wine Country, New York’s Finger Lakes region, the Northern Virginia area, and the Llano Estacado region of Texas. Many of these regions will offer wine tasting tours through the beautiful vineyards of each winery, of course with some wine to try at the end.
Drinking hard alcohol within bars is usually with mixers (soda), but can also be served “on the rocks” (with ice) or “straight up” (un-mixed, with no ice). Some of the more popular mixed drinks include vodka with Red Bull, cranberry vodka, Jack Daniels (Whiskey) and Coke, or gin and tonic. In the US, it is usually considered inappropriate to drink hard alcohol before 5pm, the end of the conventional workday. “Happy hour” is very popular, with many restaurants and bars serving discounted drinks to coincide with the end of the work day.
The US has a very strict drinking age of 21. If you're under 30 you'll probably get asked for your ID and many bars and clubs only allow entrance to those 21 and over. Most American photo ID cards have the date of birth in the format of month/day/year, and could cause some confusion for those coming from countries with a different order. It is a criminal offense to use false identification to misrepresent your age.
Depending on the state, selling alcohol is prohibited after a certain hour, which can range from 1am to 4am, except for good old Nevada where alcohol can be served 24 hours a day. It's also worth noting that some states only allow you to buy beer and wine in store, while hard liquor is sold at dedicated liquor stores or even state-managed stores that only sell certain days of the week. There are even some “dry counties” that ban alcohol in public establishments.
Most towns ban drinking in public in the streets, but with varying degrees of enforcement. There are also always bans on “drunk and disorderly” behavior. In the US, drink driving is a very serious event, especially because of the lack of a strong public transportation system. A blood-alcohol level of 0.08% is considered “under the influence, and you'll probably get chucked out of the country. Just use public transportation whenever possible, or call a taxi. Even having an open container of alcohol in the car other than in the trunk is against the law. The laws may sound strict, but generally, Americans love their drinking culture and it is a great way to meet new people and strike up conversations.