The Postman and the Postal Service comes from Ladybird series 606B - People at Work and was published in 1965. It looks like a fascinating series, and I've already featured another book from the series - The Nurse. The books in this series are written in more approachable language than some of the more detailed Ladybird books, and would be great reading practice for children learning to read.
The book begins with a look at the very early days of the postal service, five hundred years ago, when the King's letters were carried by a special messenger in a bright red uniform, the very beginning of the Royal Mail. The book explains how the service gradually developed into a network of post boys, carrying other people's letters as well as the King's letters. They travelled by horseback, and every twenty miles or so was an inn where the post boys stopped to change their horses and eat. These inns because post-houses, the very first post offices. It's a really interesting history of the development of the postal service.
The second half of the book covers the postal service as it was when the book was published, beginning with the purchase of a stamp and ending with the postman delivering a letter to the door, with plenty of rich detail along the way about the way in which letters are sorted, transported and delivered. I know that it's a process that would fascinated children - I remember well a trip to the local sorting office when I was a child! Although these days the system must be a lot more mechanical and computerised, I would imagine that many of the basics are still pretty similar.
I'm joining in with Ladybird Tuesday at Being Mrs C. You can see all my previous Ladybird Tuesday posts here.