After Christmas, which holiday sees the most greeting cards sent in the United States?

After Christmas, Valentine's Day is the holiday with the most greeting cards sent in the United States.

The holiday's card-giving tradition grew from early modern English customs in which people exchanged romantic messages, flowers, and confectionery. In the United States, Esther Howland began producing mass-market embossed paper-lace valentines in Massachusetts shortly after 1847, helping turn the custom into a major commercial tradition.

The U.S. Greeting Card Association has estimated that about 190 million Valentine's cards are sent annually, excluding the many classroom valentines exchanged by children. When school exchanges are counted, the total has been estimated at roughly 1 billion cards, making the holiday especially visible in schools.

Mother's Day is another major card-sending occasion and is sometimes confused with Valentine's Day in rankings. The distinction depends on the source and whether classroom cards are included, but the standard U.S. trivia answer for the second-largest card holiday after Christmas is Valentine's Day.