The postcard might have just saved the postal service in all of Europe. Prior to its adoption, letter delivery services in Europe charged according to weight, and collected money upon delivery, from the addressee, rather than upfront from the sender. Many of the surprised addressees understandably refused the delivery and payment, and as a result the postal service was hemorrhaging money. In Germany, a professor suggested the use of unsealed, envelope-less “open-post sheets” as a cheap form of communication, and his idea took off.

On this day, October 1, 1869, the world’s first government postal card, called the Correspondenz Karte, was born. With the stamp already pre-printed, included in the cost of the card, senders and addresses did not need to worry about postage. During the first three months after being issued, over two million of the cards were sold.

Exactly one year later the British Postmaster-General released its own “Correspondence Cards”, printed and pre-stamped by the renowned De La Rue firm. Where the postal rate for letters in a sealed envelope remained at one penny, the cards could be sent for half that rate. More than 675,000 were sold on the very first day of issue.