The Curtiss Jenny stamp was issued by the American Post in the year 1918. It is among one of the three Airmail postage stamps of US. This 24 cent stamp was one of the first to release out of the three sets of stamps.
The interesting thing about this stamp is, it consists a printing error. This stamp depicts the Curtiss JN-4 also known as Jenny, it was printed inverted in the center. It was a training military biplane, later used as a civil aircraft. This plane was the backbone of American post-war aviation.
The design of this stamp became highly valued in the Philately world. The set of four 24 cent stamps were sold in on the New York auctions for 2.97 million dollars.
Image Courtesy: ebay.com