The long lost "position 79" 1918 24c Inverted Jenny stamp made $299,000 at Leslie Hindman Auctioneers in Chicago on February 18.
The Inverted Jenny is the most celebrated American error
The lot had remained in the same collection since it was acquired from dealer Colonel EHR Green almost 100 years ago.
Green bought the unique sheet of 100 from collector William T Robey, who spotted it in a post office in Washington DC. Green then split it into singles and a handful of blocks.
Another example will sell at Robert A Siegel at the end of the month.
The record for a single Inverted Jenny stands at $1.3m, set last year by an example in immaculate condition.
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