John Mercanti autographs copies of his book, “American Silver Eagles.”

John Mercanti, former chief engraver of the U.S. Mint and the man responsible for more coin and medal designs than anyone else in the Mint’s history, took Whitman Expo attendees behind the scenes in the Mint’s transition from traditional hand-sculpting and engraving techniques to the digital age.

Mr. Mercanti, author of American Silver Eagles: A Guide to the U.S. Bullion Coin Program, recounted his long and storied designing our nation’s coinage–from his days as an illustrator in the 1970’s, through his tenure as the twelfth Chief Engraver, ending with his retirement in 2010.

Along the way, Mr. Mercanti witnessed a transition from a time when the Mint turned out a relatively small number of coin designs each year, to the much more ambitious schedule of recent years.