One often hears about the United States Postal Service motto. One of those things that everyone knows. Right?
You know:
Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds.
Wrong. The USPS has no official motto, nor has it ever had one.
So what's the story, then?
Like many old municipal buildings (hospitals, city halls, police stations, public schools), post offices have often had inscriptions. Usually some inspirational verse or quote, commonly in Greek or Latin (or derived from one or the other). That famous "motto" that everyone thinks is the USPS creed can be found at the General Post Office (also known as the James A. Farley Post Office or James A. Farley Building, after a Postmaster General) in New York City—on 421 8th Avenue between West 31st and West 33rd streets.
When the architectural firm of McKim, Mead & White designed the building in 1913, one of their people—a William Mitchell Kendall—supplied the now famous quote. According to Kendall, the quote (which would be an appropriate motto) comes from the writings of Herodotus. It "describes the expedition of the Greeks against the Persians under Cyrus, about 500 B.C." The Persians used mounted "postal" couriers as a means of relaying messages and news. So the quote, of course, is meant to suggest the devotion and determination of those whose job it was to see that the "mail" got through. A Harvard professor, George H. Palmer, supplied a translation which was considered to be the most "poetical" of seven.
To this day, those words are inextricably linked to the USPS—and postal carriers everywhere.
(Primary source: www.usps.gov/history/his8.htm)