First Highway Post Office
On February 10, 1941, the first Highway Post Office began service in the United States.
In the 1800s, America’s rapid expansion created a need for faster mail transportation. The short-lived Pony Express of 1860-61 made it possible to send messages across the country in just 10 days. Then in 1862, the US introduced its first Railway Post Office (RPO), which sorted mail as the train steamed along.