I found this account of how the Victorians invented the Christmas card in the children’s book Amazing Inventions and Concoctions, by Howard Elson, illustrated by Kim Blundell (London: Octopus Book 1988). This says
‘Every Christmas, it’s a great ritual to send out greetings cards to your friends and relatives, and the card industry is a thriving business all over the world.
The Christmas card was first designed in 1843 by an Englishman called J C Horsley for his friend, Sir Henry Cole. The card, printed on stiff brown cardboard, depicted a sketch of a family eating, drinking and making merry. The words, “A Merry Christmas And A Happy New Year To You”, were printed underneath. 1000 were put on sale in London.
Americans had to wait 32 years before Christmas cards were introduced in the US by Louis Prang of Boston, Massachusetts.’
The BBC showed a programme on the origin of various Christmas customs the other year, which covered the invention of Christmas cards. According to them, Horlsey invented it because he had so many friends he was tired of having to write complete letters to them all. Well, it’s great to be so popular!