On 21st May 2018, the United States Postal Service issued two airmail forever stamps to commemorate the 100th anniversary of the airmail service. These two stamps depict similar design but are different in colour.
In the middle of the World War I in 1918 an airmail service was started by a small group of army pilots. They delivered the post on the routed linked to Washington DC, Philadelphia and New York City. It was one of the first initiatives in the world for regular scheduling of airmail services. The United States Postal Service took over this service in late August in the same year.
These stamps commemorated and celebrated the courage and foresight behind this service. These stamps were printed in intaglio, a design engraved on the stamp paper. The design of the plan illustrated on this stamp was used in the early day of service called JN-4H biplane. The same plane appeared on the stamp issued to mark the beginning of this service.
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