Born in Philadelphia on April 27, 1943, John Mercanti was educated at the Pennsylvania Academy of Fine Arts (briefly), the Philadelphia College of Art, and the Fleisher Art School. He joined the U.S. Mint staff in 1974 and served as sculptor and engraver. During his tenure at the U.S. Mint from 1974 to 2010, Mercanti designed over 100 coins and medals. He was appointed 12th chief engraver of the U.S. Mint with the added title "Supervisor of Design and Master Tooling Development Specialist" by Director of the U.S. Mint Edmund Moy.
In its May 28, 2006 issue, the E-Sylum pointed out: "John has been the de facto chief engraver for some time, but the department he will now officially lead is vastly different than it was even a few years ago. The Treasury has spent millions of dollars on the latest technology, using computers and 3D laser modeling machines to automate much of the coin design process. Reduction machines have become obsolete – dies are now cut directly from computer models."
John Mercanti enjoyed his work designing state quarters as shown by his comments in a Fortune magazine interview: "I’ve made quarters for Pennsylvania, North Carolina, Iowa, West Virginia, and Arkansas. The individual states supply the Mint with a written concept. My division comes up with the visual interpretations. Then the state votes on them, or sometimes the governor makes the decision, but the Treasury Secretary has to sign off on everything we do. Ultimately the [state] picks the design, and we begin sculpting it. We transfer our design to an eight-inch round clay model, which in turn is transferred to plastic. An engraving and transferring machine, called a Janvier, reduces the artwork to a coin size on a piece of steel. It can take months to make one. The best part of my job is seeing the finished product–holding the coin in my hand. It’s satisfying to see them all over the country."
For the American Arts commemorative medallion series he designed the 1982 Louis Armstrong one-ounce, the John Steinbeck half-ounce, and the 1984 Helen Hayes one-ounce pieces. He also designed the obverse for the Hubert Humphrey medal, the reverse of the Ronald Reagan medal, the reverse of the 1986 silver eagle, the 1984 Olympics Gold $10, the 1986 Statue of Liberty Silver $1, the 1989 Congress Bicentennial Gold $5, the obverse of the 1991 Mount Rushmore Gold $5, and the obverse of the American Platinum Eagle program begun in 1997. In addition to his work for the Mint, Mercanti designed medals for the American Numismatic Association (1989 Pittsburgh annual convention medal and others) and created illustrations for the U.S. Army, Navy, and Marines.
In 2017 John Mercanti received the David Rittenhouse Award.