On July 1, 1863, the US Post Office inaugurated its free City Mail Delivery Service in part in response to the Civil War. By the end of the first year, 65 cities offered the service and employed 685 mail carriers.
On June 10, 1840, Senator Daniel Webster submitted a resolution to the US Congress recommending that the US issue stamps. He was inspired by the success of Britain’s recently issued Penny Black, and proposed the US follow their example.
On May 18, 1990, the USPS issued an experimental plastic stamp to test the popularity of selling stamps through Automatic Teller Machines (ATMs). While the plastic stamp proved unpopular, especially with environmentalists, the ATM format proved to be a success.
On May 9, 1918, the US War Department created the Military Postal Express Service (MPES) to handle military mail in Europe during World War I. It was the first postal system in the world to be created by an Army.
On May 7, 1833, future President Abraham Lincoln took a job as postmaster for New Salem, Illinois. Holding that position for three years, he was well-liked and respected for his commitment to his postal customers.
On April 20, 1987, the USPS issued the set of eight Special Occasions stamps, the first “special” stamp booklet.
On April 8, 1930, Guam Guard Mail stamps were introduced for inter-island mail. Issued in small numbers, they were only in use for a year.
On April 3, 1860, the Pony Express made its first trip from St. Joseph, Missouri, to Sacramento, California. Though short-lived, the Pony Express was a revolution in communication, able to transport important letters across the country more than twice as fast as the existing overland mail system.