In 4th grade our school started doing a mailing intra-school pen pal program. We would write letters to kids in other classrooms and students would act as mail carriers to deliver it. The point of the program was to teach how to address envelopes and how to properly write letters. Part of the program included taking a tour of our local post office.
This video reminds me of that tour, although our local post office was not this busy. The USPS and Smithsonian Institution give a behind the scenes video of how your mail gets from point A to B.
Found via Letter Love
