Into the 1960s, much of the nation’s mail moved on railroads. Passenger trains carried Railway Post Office (RPO) cars equipped with sacks and slots that allowed clerks to sort mail en route. Sorted mail was delivered, and new letters were picked up, as the train passed through each town. It was complex work, and required a high degree of speed and accuracy. Clerks took regular examinations to keep their skills well-honed.
Sharp clerks practiced for their exams with kits like this one. It belonged to Richard Loida, a St. Paul-based postal clerk who made frequent RPO runs to Duluth and the Dakotas in the years after World War II. The kit consists of a wooden box, about the size of a briefcase, which opens to reveal slots labeled with primary railroad junctions; and a box of cards for each post office in Minnesota. Mr. Loida would practice placing the cards into the appropriate slots as quickly and correctly as he could. RPO clerks were required to sort as many as 600 pieces of mail per hour, and needed to score 97% to pass their exams. Needless to say, a little practice wasn’t a bad idea.