C3a - 1918 24¢ Jenny Invert
US #C3a – 1918 Inverted Jenny

On May 14, 1918, stamp collector William Robey discovered the now sought-after Inverted Jenny, #C3a.

The Bureau of Engraving and Printing was in a rush to produce America’s first airmail stamp. Because the stamps were to be bi-colored, each sheet would be fed through the press twice – once to print the red frame and a second pass to print the blue vignette. In the rush, nine of the 20,000 sheets printed had been hand-fed through the printing press upside down. The mistake created an inverted vignette and positioned the plate number on the bottom selvage. At some point, eight sheets were found in the BEP office and destroyed. However, a single sheet made its way to the New York Avenue post office branch in Washington, DC.

1918 24¢ Curtiss Jenny, carmine rose & blue
US #C3 – non-error Jenny stamp

Stamp collector William Robey eagerly awaited the first airmail flight. The young Washington, DC, resident planned to exchange covers with special “first trip” postmarks with fellow collectors at the other two points of the tri-city route.

At the age of 29, Robey was an experienced collector of error stamps and knew the potential for inverts associated with bi-color printing. On the same day printing began on the stamps, Robey advised a fellow collector, “It might interest you to know that there are two parts to the design, one an insert into the other, like the Pan-American issues. I think it would pay to be on the lookout for inverts on account of this.”

4806 - 2013 $2.00 Inverted Jenny, sheet of 6
US #4806 – The selvage pictures the National Postal Museum, aviation pioneer Reuben H. Fleet, a map of the first scheduled Air Mail route, and a compass rose.

Unaware that the first 24¢ airmail stamps had already been distributed and placed on sale the previous afternoon, William Robey planned a special trip to the post office on the morning of May 14th. As he left his one-bedroom apartment, Robey told his young bride, “I have a very strange feeling there’s going to be a mistake.”

1993 29¢ National Postal Museum: Stamp and Bar code
US #2782 honors the opening of the National Postal Museum and pictures a Jenny Invert.

Some of Robey’s recollections grew fuzzy over the years, but many essential facts are clear. The young office clerk withdrew $30 from his bank account, a figure equal to more than $1,500.00 in today’s wages, to purchase a full sheet of the new stamps.

1918 24¢ Jenny Invert (C3a) Reproduction
Item #C3a Repro – You can add the history and excitement of the Jenny Invert to your collection with this reproduction sheet. Click on the image for other formats including single stamps and blocks.

Shortly after noon, Robey entered a branch of the post office in Washington, DC, and asked for a sheet of 100 of the 24¢ airmail stamps. When the unknowing clerk placed the sheet of inverted stamps on the counter, Robey said his “heart stood still.” After paying for the sheet without comment, Robey asked the clerk if he had additional sheets. The clerk apparently realized something was amiss, closed his window, and contacted his supervisor.

Robey’s search of other post office branches was unsuccessful. He returned to his office and shared his news with a fellow stamp collector, who immediately left the office to search for more error sheets. His activities alerted authorities, who arrived at Robey’s office less than an hour after he returned from the post office. The officials threatened to confiscate the sheet of inverts, but Robey stood firm.

4806b - 2013 $2.00 Imperforate Inverted Jenny Sheet of 6
US #4806b – Imperforate 2013 Inverted Jenny Sheet

Alerted to the error, authorities immediately halted sales of the 24¢ airmail stamp in Washington, DC, Philadelphia, and New York City as they searched branch offices for other sheets.

Robey’s actions in the hours following his discovery suggest that he never considered keeping the inverted stamps. Instead, he contacted Washington stamp dealer Hamilton F. Coleman immediately. Coleman offered to purchase the sheet for $500 – an amount equal to more than $26,500 today. Robey declined the offer. Robey’s decision was a gamble. The value of any particular stamp is based on the law of supply and demand. Although errors in general – and inverts in particular – are highly valued, the extent of the BEP’s error was unclear that afternoon.

2013 $2.00 Upright Jenny Pane of 6 Stamps
US #4806d – RARE 2013 Upright Jenny pane – only 100 were produced!

After riding around on streetcars for hours pondering his options, Robey slipped into his apartment under the cover of darkness. Mindful of the government threats and the potential value of his stamps, Robey and his bride slept with their newly found treasures hidden under the bed.

Because the 24¢ airmail stamps were still in production, the BEP reaction to the news of an invert was swift and certain. On May 15th, new procedures were implemented to prevent further printing errors. Shortly thereafter, still another change was made to reduce the risk. Each “generation” can be distinguished from the others by the selvage and its characteristics.

M11292 - 2013 Inverted Jenny Collector Kit
Item #M11292 – 2013 Inverted Jenny Collector Kit (click the image to see what it includes)

Meanwhile, William Robey raced to sell his stamps before the government made good on their threat to take them. He spent several days contacting and visiting stamp dealers. In the end, he sold the sheet to Eugene Klein. He sold the sheet that he bought for $24 to Klein for $15,000 – a 62,500% profit over the purchase price! Days later, Klein would sell the sheet to Colonel Edward H.R. Green for $20,000. They broke up the sheet and numbered each stamp, which has allowed generations of stamp collectors to trace the ownership of each stamp. In 2005, Mystic became the proud owner of the Inverted Jenny Plate-Number Block, before selling it in 2014. Nine years later, it went to auction and sold for $2 million.

Click here to trace the provenance of each Inverted Jenny from the sheet of 100.

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  1. I’m explaining to my family that each stamp is a story on to itself and no just a “sticky thing” that fills a void in a collection. Fascinated since a child and forty years have a nice, not large collection of mint stamps.

  2. Today most lottery winners seem to spend all their money very quickly. But, I remember reading that Robey purchased a house and even financed his daughter’s wedding years later. I’m still amazed that Robey was specifically looking for an error sheet. What were the odds that he would be the one to find it – the only one?

  3. Really only one sheet, thought there were more ! Robey scored and knew how to make his good luck pay off, good for him.

  4. After news of Robey’s discovery became public the Post Office Department stopped selling the airmail stamps and inspected all the sheets. They found 9 or 10 additional sheets with plane inverted and destroyed them. Too bad for collectors but the POD was embarrassed to have an error for their new service.

  5. I believe someone should have taken another airmail sheet of stamps, one without mistakes, into the air and done half of an inverted loop with an “Immelmann” flip-over at the top. Then the pilot could have landed, signed each stamp, and sold them as a “certified upside-down flight” souvenir in 1919. The U.S. had pilots that could have done that, based on World-War I dog-fighting experience.
    And later, maybe the Germans could have tried the same stunt with their Zeppelins left over from World War I.

  6. The post office learned its lesson on how to devalue their mistakes. When they inverted the second pass of the Dag Hammarskjold stamp, in 1962 the post office simply printed millions of the error. I was only 13 at the time, but a passionate collector. What a disappointment to find that my “error” Dag Hammarskjold was as common as a lightning bug in the summer!

    1. I was the same age and an avid collector then. I remember the disappointment when I found out my “error” stamp was essentially worthless. I already had big plans for the money I would make of the sale. I still enjoy looking at that stamp, though, and thinking about “what might have been.”

    2. Born in 1950 I was 12 years old and an avid young stamp collector at the time of the Hammarskjold incident, encouraged by my father. I seem to remember that there was a great deal of anger among collectors that the post office would produce an error on purpose.

  7. As a QA Engineer I wonder what steps the BEP took to prevent this from happening again. Remember this was decades before Edwards Deming would literally write the book on Quality Control.

    1. Yup. As a 13 year old seeing what happened to the Dag, I told my self don’t tell anyone you have a mistake. Don’t sell either.

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