1. How do American people celebrate Valentine's Day? Reference: Every February 14, across the country, candies, flowers especially roses, which symbolize love, and other gifts are exchanged between loved ones, all in the name of st Valentine. Giving Valentine 's Day greeting cards is also one of the activities of this day1. How do American people celebrate Valentine’s Day? Every February 14, across the country, candies, flowers, especially roses, which symbolize love, and other gifts are exchanged between loved ones, all in the name of St. Valentine. Giving Valentine’s Day greeting cards is also one of the activities of this day. Reference: