The Inverted Jenny is a United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 postage stamp

Postage stamp

A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...

 first issued on May 10, 1918 in which the image of the Curtiss JN-4

Curtiss JN-4

The Curtiss JN-4 "Jenny" was one of a series of "JN" biplanes built by the Curtiss Aeroplane Company of Hammondsport, New York, later the Curtiss Aeroplane and Motor Company. Although the Curtiss JN series was originally produced as a training aircraft for the U.S...

 airplane

Fixed-wing aircraft

A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 in the center of the design was accidentally printed upside-down; it is probably the most famous error in American philately

Philately

Philately is the study of stamps and postal history and other related items. Philately involves more than just stamp collecting, which does not necessarily involve the study of stamps. It is possible to be a philatelist without owning any stamps...

. Only one pane of 100 of the invert stamps

Invert error

In philately, an invert error occurs when part of a postage stamp is printed upside-down. Inverts are perhaps the most spectacular of a postage stamp errors, not only because of the striking visual appearance, but because they are almost always quite rare, and highly valued by stamp...

 was ever found, making this error

Invert error

In philately, an invert error occurs when part of a postage stamp is printed upside-down. Inverts are perhaps the most spectacular of a postage stamp errors, not only because of the striking visual appearance, but because they are almost always quite rare, and highly valued by stamp...

 one of the most prized in all philately. A center-line block catalogs for $600,000, which is probably low; a single inverted Jenny was sold at a Robert A.