In 1892 St. Louis, Missouri added specially-outfitted cars to their mail vehicles. The service sped up mail deliveries, making it especially popular with businesses. Twelve other cities across the country jumped on board. By 1908 there were mail trolleys in Brooklyn, Boston, Chicago, Cincinnati, New York, Philadelphia, Washington, D.C., San Francisco, Rochester, Pittsburg, Seattle and Cleveland. Electrically-powered trolleys offered the opportunity for clerks to use electrically-powered canceling machines on board. What was fast became even faster. Between trolleys and multiple daily deliveries in large cities, individuals or businesses could send and receive letters as many as three to four times a day! That may not sound like much in our age of texting, but it was extraordinary to individuals at the turn of the last century.
Mail trolleys were a great success, but everything has its day. In 1913 Parcel Post Service began and instead of sacks of letters, clerks had sacks and sacks of packages to process. Far more in weight and volume than they could handle in the relatively tiny cars. About the same time the Post Office had begun using trucks to carry mail. Most cities stopped using mail trolleys between 1913 and 1919. Baltimore’s trolleys kept going until 1929, but after that, mail trolleys were no more.
Credit: Exhibition overview from museum website