“Carrier Stamps” is the term used for stamps which prepaid the fee for service in taking a letter to or from the post office, or between letter-writers in the same city. Carrier stamps were issued in $.01 or $.02 denominations, and the practice of using them continued from 1836 to 1863, when the government Post Office Department began paying carriers a regular salary.
There was a period when carriers issued their own stamps, beginning in 1835 when the Northern Liberties News Room imprinted lettersheets with a non-denominated design, representing the fee paid to Northern Liberties News Room for carrying the letter to the Philadelphia post office. There were also semi-official carrier stamps issued by the men who served in the carrier departments of city post offices. Thus, a stamped letter could be dropped into a mailbox for pickup and delivery to the post office.
The first stamp ever used under government authority is a carrier, a 3c stamp (Black and Blue) accepted by the New York City carrier department in 1842 after they bought the private firm known as the City Despatch Post. The government itself issued two carrier stamps in 185 1 (the Franklin and Eagle carriers). They were created to make it easier to pre-pay the carrier fee and were used in large cities for many years.