Valentine's Day cards have been exchanged since the early 15th century when Charles, Duke of Orleans sent letters to his wife while imprisoned. In the 19th century, Esther Howland began mass producing and selling Valentine's cards in the United States. The early 1900s saw Valentine's card manufacturing become a business, with one early company being Norcross. Today, Valentine's Day card giving is a large tradition in America, second only to Christmas cards.
3. History
• The first and oldest valentine’s love letters
were sent from prison by Charles, Duke of
Orleans in 1415 for his wife
http://www.novareinna.com/festive/valcard.html
4. • In 1850, Esther Howland, an American printer
and artist was among the first to publish and
sell Valentines in the United States.
• In the early 1900's a card company named
Norcross became one of the first companies
to manufacture Valentines.
• With the exception of Christmas, Americans
exchange more cards on Valentine's Day than
any other time of year.
http://www.emotionscards.com/museum/vals.html