New York Times
By MATTHEW HEALEY
Published: October 20, 2005
“A block of four United States airmail stamps with the airplane in the center famously – and erroneously – printed upside down was auctioned yesterday evening in New York for $2,970,000, a world record for a stamp item.
The 1918 stamp, known to collectors as the Jenny because of the Curtiss JN-4 biplane depicted in the design, was the first American issue for air postage. Its value was set at 24 cents.
But of roughly two million printed, 100 bore the topsy-turvy center plane and became known as the Inverted Jenny. They quickly became the stuff of philatelic legend.”