Heaton, Augustus Goodyear (1893)
Although auction cataloguers sometimes recorded mintmarks prior to Heaton (Woodward's 46th sale in 1882, for example, mentions a prooflike 1870-CC dollar), Heaton was the first to formally investigate the issue and publish his findings. To be sure, the book is full of inaccuracies, such as his discussion of 1873-CC dimes, but to quibble over such points ignores the game changing nature of Heaton?s tome, for this book marks the genesis of branch mint rarity, a concept previously only considered on a date-by-date basis. Now the 1870-S dollar (unmentioned in Heaton, by the way) could be compared with delicacies such as 1827 quarters and 1822 half eagles. A hundred years would elapse before late twentieth century collectors further expanded the definition in order to radically embrace condition rarity. Still, although revolutionary in 1893, this volume has been superceded by many references, and remains a book more significant for being the first of its kind, than for its actual content. Voted #30 of the top one hundred items of numismatic literature by the Numismatic Bibliomania Society.