The earliest known American birthday cards were printed in the 1870s by publishers like Jonathan King and Louis Prang, whose colorful designs helped popularize the Christmas card. However, the tradition of sending yearly cards to celebrate birthdays didn’t catch on until the beginning of the 20th century.
The first birthday cards were made in a flat postcard style followed by folded cards in the 1910s, just as the Hallmark company was launching. Book-style birthday cards took off in the 1940s and ‘50s, often featuring designs with comical cartoon animals. For the last several decades, even in the Internet age, birthday cards have held their position as the most commonly produced type of greeting card.