Today we're going to discuss the history of the postal service. In the 19th century, the introduction of the penny post in Britain revolutionized communication. Before that, the recipient, not the sender, usually paid for the mail, which was expensive and often refused. The reform, led by Rowland Hill, proposed a uniform low rate paid by the sender. This change dramatically increased the volume of letters. Interestingly, the first adhesive postage stamp, the Penny Black, was issued in 1840, but it was only valid for one day, making it a collector's item today.