This variety, due to its boldness and clarity, has always been a popular variety. It was discovered only a year after it was minted and it was documented in The Numismatist.
The only overdate produced in the entire Saint Gaudens series! It is understood that sometime in 1908 while making dies one of the die sinkers somehow received a 1908 hub and used it to make his impressions for the 09 coinage. Normally the engraver would notice such errors, but Charles Barber was too busy giving his attention to the newly released quarter and half eagles designed by Bela Lyon Pratt less than a year earlier. If this error was noticed during production no one bothered to condemn or correct it. A very interesting piece and noteworthy coin.