Valuable U.S. stamps include the 1918 inverted Jenny Curtiss, 1867 Abraham Lincoln, and 1867 Benjamin Franklin stamps. A block of four inverted 1918 Jenny Curtiss stamps sold at auction for $2.97 million in 2014 after previously selling for $1.1 million in 1989, making it the most valuable American stamp to date.
The inverted Jenny Curtiss stamp features an image of an upside-down military biplane due to a printing error. The postal service only issued 100 of these misprints, and collectors have only discovered one complete block of four. Individual stamps can sell for $200,000.
The 1867 Abraham Lincoln stamp is the oldest stamp that individuals can use as current postage, but the stamp can sell for $200,000. The U.S. government issued the stamp during a postage revamp in the middle of the Civil War. The 15-cent face value was unusually high at the time of printing, contributing to the stamp’s rarity. The stamp featured a new printing method called grilling which discouraged senders from reusing stamps. The stamp's “Z” grill with horizontal ridges is especially rare.
An even rarer 1867 stamp features Benjamin Franklin; only two known existing examples remain. Collectors value the stamp at $935,000. This stamp features the same rare “Z” grill, a side profile of Franklin and a 1-cent face value.