How long is the validity of American tourist visa and the longest stay?

You can apply for an American tourist visa valid for 3 months, 1 year, 3 years, 5 years, or 10 year, but generally you can stay for up to 6 months each time (180 days). The specific stay time is determined by the customs. When entering the country, stamp your passport and write down the date of departure. Under normal circumstances, you can give 1.