10% off all photos on 500px Prime until July 31Start exploring now!

"In the United States a railway post office, commonly abbreviated as RPO, was a railroad car that was normally operated in passenger service as a means to sort mail en route, in order to speed delivery. The RPO was staffed by highly trained Railway Mail Service postal clerks, and was off-limits to the passengers on the train." (Quoted from Wikipedia)

Discover more inspiring photos like this one.

Download the FREE 500px app Open in app