In an effort to rekindle the public’s excitement over stamp collecting and interest a new generation in the hobby, the United States Postal Service has created an instant stamp rarity — a twist on one of the world’s most famous and valuable stamps.

The campaign involves the post office’s recent reprint of the classic 95-year-old stamp error known to collectors as the Inverted Jenny, which shows a Curtiss JN-4 biplane, or a “Jenny,” printed upside down.

That 24-cent airmail stamp, America’s first, was intended for mail carried on an experimental air service between Washington and New York. One bright morning in 1918, a collector named William T. Robey walked into his local post office to buy some stamps, and his life was changed forever.

When Mr. Robey spotted the glaring misprint, he knew he had struck gold. He promptly resold his full sheet of 100 inverts to a dealer and bought himself a new house with the proceeds.