Good morning, everyone. Today we're going to discuss the history of the postal service. Before the 19th century, sending a letter was very expensive, and it was paid by the recipient, not the sender. In 1840, Britain introduced the Penny Post, which was a major reform. This system made postage affordable for ordinary people, and it was paid in advance by the sender. Interestingly, the first adhesive postage stamp, the Penny Black, was also introduced that same year. However, it wasn't until 1850 that other countries, like the United States, began to adopt similar systems. So, the key change was the shift in who paid and when.