As long as there has been government-sanctioned mail service, there have been entrepreneurs undercutting the official lines with faster, cheaper, or more reliable alternatives. Sometimes private posts offered services beyond what the official Post Office Department offered, but at other times private companies competed head-on.
The long-running debate over whether the Post Office should hold a monopoly on mail services rests on the question of universal service: must the Post Office provide equal access to the mail for all residents?
Universal service is expensive. It costs more to deliver a letter to the distant rural corners of the country than to deliver a letter within an urban center. With the burden of universal service, the Post Office has always been at a disadvantage to private companies that serviced limited routes.
The Post Office Act of 1792 clearly prohibited the lucrative business of sending letters by private companies on post roads, but it allowed printers to send newspapers and pamphlets by private courier. The 1845 Postal Reform Act reinforced the prohibition of sending letters by private post but remained ambiguous on other forms of media. Private companies were also allowed to deliver packages over four pounds, a service not offered by the Post Office Department until the introduction of Parcel Post in 1913. The debate continued for decades until the United States Postal Service’s monopoly was finally established in the 1970s. Yet this monopoly only applies to first class mail.
Private postal company mailboxes are just one type of artifact that tells this fascinating story. You can see some of the 'locals'—stamps issued by private companies for their mail services—in the philatelic section of this website.