1918 Inverted Jenny C3a: The $2 Million Stamp Error Value & Price Guide

On May 14, 1918, a stamp collector named William T. Robey walked into the New York Avenue post office in Washington, D.C., and bought a sheet of 100 stamps. He paid $24. The stamps were the brand-new 24-cent airmail issue (Scott C3), featuring a Curtiss JN-4 biplane, commonly known as a Jenny. But on Robey's sheet, every single airplane was printed upside down. He had just made the most famous purchase in philatelic history.

Quick Value Summary

• Item: 1918 24-cent Inverted Jenny (Scott C3a)

• Year: 1918

• Category: Stamps

• Condition Range:

  • Single stamp, straight edge, disturbed gum: $500,000 - $700,000
  • Single stamp, fully perforated, fine centering: $800,000 - $1,200,000
  • Single stamp, superb centering, full gum: $1,500,000 - $2,000,000+
  • Block of four: $3,000,000 - $5,000,000+ (if one surfaced)

• Record Sale: Position 49 stamp sold for $2,000,000 at Siegel Auction Galleries in 2023

• Total Known: Exactly 100 stamps from one sheet. All are accounted for.

The Story

The United States Post Office Department issued its first airmail stamps on May 13, 1918, the day before the inaugural US airmail service flight between Washington, D.C., and New York City. The 24-cent stamp depicted a Curtiss JN-4H "Jenny" biplane in flight, printed in blue with a red border frame. The printing required two passes through the press: one for the red frame and one for the blue airplane vignette. If a sheet was fed into the second press run incorrectly oriented, the airplane would print upside down relative to the frame.

William Robey was an experienced collector who knew about printing errors. He arrived at the post office early on May 14 specifically hoping to find an invert. When the postal clerk showed him a sheet, he immediately spotted the inverted planes and purchased the entire sheet of 100 stamps for $24 (the face value).

Robey's initial attempt to sell the sheet was complicated. He first offered it to several collectors and dealers. Within a week, he sold it to Philadelphia dealer Eugene Klein for $15,000. Klein immediately sold the sheet to Colonel Edward H.R. Green (son of the legendary "Witch of Wall Street" Hetty Green) for $20,000. Green broke the sheet into singles and blocks, distributing stamps to various dealers and collectors over the following years.

Of the 100 stamps, 84 had full perforations on all four sides, and 16 had one straight edge (from the sheet margins). Straight-edge stamps are worth less. The positions of each stamp within the original sheet have been tracked by researchers, and every stamp has a documented provenance.

The most famous individual stamp is Position 49, which sold for $2,000,000 at Robert A. Siegel Auction Galleries in November 2023. Another notable stamp, the "stolen" Position 76 (one of four stolen in 1955 and gradually recovered), resurfaced in 2016 and was returned to its rightful owner's estate.

How to Identify It

• Design: A Curtiss JN-4H biplane flying INVERTED (upside down) within a red border frame. The normal C3 stamp shows the plane right-side up.

• Color: Blue center (airplane) with red frame and border.

• Denomination: 24 cents.

• Perforation: Perf. 11.

• Size: Approximately 22mm x 25mm.

• Scott Number: C3a (the invert). The normal stamp is C3.

• Quantity: Exactly 100 stamps exist. Every one is documented and catalogued.

Critical notes:

• The 2013 USPS reissue of a $2 "Inverted Jenny" stamp is a deliberately produced tribute, not an error. It has no significant collector value beyond face.

• Every genuine C3a has a documented position number from the original sheet. Provenance documentation is essential.

• Any C3a offered for sale without clear provenance should be treated with extreme suspicion.

Value by Condition

Straight Edge Examples: 16 of the 100 stamps had one straight edge from the sheet margin. These sell for $500,000 to $700,000 depending on gum condition, centering, and overall appearance.

Fully Perforated, Average Centering: Stamps with perforations on all four sides but off-center placement. Most C3a stamps have centering issues, as the two-pass printing process made perfect registration difficult. Expect $800,000 to $1,200,000.

Fully Perforated, Fine to Very Fine Centering: Better-than-average centering makes a significant difference. These sell for $1,200,000 to $1,500,000.

Fully Perforated, Superb Centering, Full Original Gum: The pinnacle. Position 49, one of the best-centered examples, sold for $2,000,000 in 2023. Only a handful of stamps in the sheet achieve this standard.

Blocks: Colonel Green broke the sheet into singles and a few blocks. If a block of four were to come to market (no intact block has sold publicly in decades), it would likely exceed $3,000,000.

Value factors:

• Position number: Each of the 100 stamps has a documented position. Some positions have more storied histories than others, affecting desirability.

• Centering: The single most important quality factor after authentication.

• Gum condition: Original gum (OG) is preferred. Never-hinged (NH) gum is essentially nonexistent for these stamps given their age and handling history.

• Provenance: A stamp with a well-documented chain of ownership from recognized collections may sell for a premium.

Authentication

Authentication for the Inverted Jenny is unlike any other stamp:

• Every stamp is known: The Philatelic Foundation and Siegel Auction Galleries maintain detailed records of all 100 stamps. Any stamp offered for sale can be verified against the census.

• Expert certification required: The Philatelic Foundation (New York) is the gold standard for C3a authentication. Their certificate confirms position, condition, and genuineness.

• Forgeries exist: Counterfeit Inverted Jennys have been made, usually by altering or reprinting a normal C3 stamp. Expert examination can detect differences in ink, paper, and printing characteristics.

• The "stolen four": Positions 5, 9, 13, and 76 were stolen in 1955. Three have been recovered; Position 9 remains missing. Any C3a offered without provenance might be the stolen Position 9, which carries legal complications.

Where to Sell

• Robert A. Siegel Auction Galleries: The premier US philatelic auction house and the firm most closely associated with the Inverted Jenny. They have handled more C3a sales than any other auction house.

• H.R. Harmer: Another established philatelic auction house with international reach.

• Sotheby's or Christie's: For stamps at this price level, major auction houses occasionally handle sales, particularly when they are part of larger collections.

• Private treaty: Given the small number of potential buyers, private sale through a specialist dealer is common for C3a stamps.

• Insurance and security: A C3a stamp requires specialized fine art insurance and secure handling. Auction houses typically provide these services.

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Explore More

The Inverted Jenny is not just a stamp error. It is the stamp error, the most famous misprint in American philatelic history and arguably the most famous stamp in the world. If one of the 100 known examples comes your way, you will know it by its provenance, its certificate, and the upside-down airplane that changed one man's $24 investment into a cultural icon.

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