Million dollar mistake: A 24-cent stamp became one of America’s rarest due to a printing error. It turned the stamp into a collector’s prize worth $2 million

Some everyday objects become valuable not because they were made to be rare, but because something unexpected happened to them. A printing error, a limited production run or a mistake that was missed at the time can sometimes turn an ordinary item into a collector's prize years later. One of the best-known examples in American history is a 24-cent postage stamp issued in 1918, which went on to become one of the country's most famous and valuable stamps.

Known as the “Inverted Jenny”, the stamp featured a Curtiss JN-4 aircraft printed upside down inside a red frame. Only 100 of the incorrectly printed stamps were sold to the public, and their unusual appearance quickly made them highly sought after by collectors. More than a century later, one of them sold for $2,006,000 at a New York auction, showing how a small printing error could turn an inexpensive piece of postage into a multimillion-dollar collectible.

The stamp was made for America's new airmail service

As per Science blog, the story began in 1918, when the United States was preparing to start regular airmail service. The new 24-cent stamp was created for the occasion and featured the Curtiss JN-4 biplane, the aircraft being used for the early airmail flights.


The stamp needed to be printed in two colours. The red frame was printed separately from the blue aircraft in the centre. Because of this, each sheet had to pass through the printing process twice.

During production, one sheet was accidentally placed the wrong way around before the second colour was printed. The result was an entire sheet showing the aircraft flying upside down.

The error was not spotted before the sheet reached a Washington post office.

William Robey noticed the mistake

On May 14, 1918, Washington clerk and stamp collector William Robey went to the post office on New York Avenue to buy some of the new airmail stamps. He asked for 100 stamps and was handed a complete sheet.

Robey quickly noticed that something was different. Instead of the aircraft appearing normally inside the frame, every plane was upside down.

He paid $24 for the sheet and kept it rather than using the stamps for postage. The mistake was soon discovered by postal officials, who wanted the sheet back. According to accounts of the episode, inspectors visited Robey at his workplace and also questioned his wife at home.

Robey refused to surrender the stamps. He eventually took the sheet to Philadelphia, where stamp dealer Eugene Klein bought it for $15,000. The sale turned a $24 purchase into a huge profit for Robey.

Klein later sold the sheet to wealthy collector Colonel Edward Green for $20,000. Green divided the sheet into individual stamps and smaller groups, marking the positions of the stamps on the back.

That is why surviving Inverted Jennys are often identified by numbers such as Position 49, Position 66 and Position 76.

One block was stolen from an exhibition

The history of the 100 stamps became more complicated as they moved between collectors.

Four of them were eventually owned together by collector Ethel McCoy. She bought the block in 1936 for $16,000 and later lent it to the American Philatelic Society for an exhibition in Norfolk, Virginia, in 1955.

During the exhibition, someone cut through the display case and stole the block.

Two of the four stamps were eventually recovered. Position 76 resurfaced in 2016 when a young man in Britain took it to a New York auction house after inheriting it from his grandfather. He reportedly did not know the full history of the stamp.

The FBI and the Manhattan US Attorney's office later helped return it to the American Philatelic Research Library. Position 66, however, has never been recovered.

Position 49 remained hidden for decades

The stamp that eventually set the $2 million record was Position 49. It had spent around a century in the same family's possession and was kept inside a bank vault for much of that time.

Because it had seen very little light and had not been placed in an album, its condition remained unusually good. Robert A. Siegel Auction Galleries described it as one of the finest-centred surviving examples.

In November 2023, the stamp went up for auction in New York. Bidding reached $1.7 million before the final costs and commission pushed the total to $2,006,000.

The buyer was 76-year-old collector Charles Hack. He already owned other Inverted Jennys and had been interested in the stamp since childhood.

Hack told The Washington Post that he had been watching the famous stamp for years and called it the “holy grail of postage”.

A mistake worth millions

The Inverted Jenny has remained famous because several unusual factors came together. It was linked to the beginning of America's regular airmail service, only 100 were originally sold, and all of them carried the same striking printing error.

The stamp has even appeared in popular culture. In a 1993 episode of The Simpsons, Homer sees a sheet of Inverted Jennys at a yard sale. He notices that the airplane is upside down but fails to understand its value and throws it aside.

The US Postal Service also brought the stamp back into the spotlight in 2013 by issuing a souvenir sheet featuring the Jenny. It also produced 100 panes with the airplane printed correctly and sold them without allowing buyers to see which version they had received. A later inspector general review found that the move violated internal rules concerning the creation of rarities for revenue.