Today we're going to discuss the history of the postal service. Before the 19th century, letters were usually delivered by private messengers, which was expensive and slow. In 1840, Britain introduced the Penny Post, a system where the sender paid a uniform rate of one penny for any letter weighing up to half an ounce. This innovation greatly increased the volume of mail. However, it wasn't until the 1860s that the railway network allowed for faster and more reliable delivery across the country. Later, in the 20th century, airmail became common, but it was initially reserved for urgent correspondence due to its high cost.