Above: Souvenir cover from first Highway route.
February 10, 1941 the first Highway Post Office service began between Washington, D.C. and Harrisonburg, Virginia. Special buses were used for this service. They were configured to allow clerks to sort the mail in transit. There was a Railway Post Office service, but rail travel was rapidly declining so the Highway service was started to replace that service.
Above: President Roosevelt mailing the first letter (National Postal Museum)
The expansion of the service was delayed by World War II. In 1946 a second route was created. The buses became a common site on American highways during the 1950s and 1960s. Each route served about 25 post offices.
Above: 1941 White Post Office bus (National Postal Museum)
In the 1970s the Post Office Department reorganized and began taking mail to regional sorting plants where it was processed using high-speed machinery. As a result the buses were phased out. The last run took place June 30, 1974. The service had been in existence for 33 years.