12 (1 Dozen OF The Same Design)United States Mint Philadelphia Mint 151 N Independence Mall East, Philadelphia PA 19106 Congress approved a new building for the Philadelphia Mint on August 20th, 1963. The Philadelphia Mint became fully operational in 1969. The structure is in the modern style and occupies an entire block in downtown Philadelphia. Philadelphia is the place where all new coins are developed by the U.S. Mint’s staff of sculptors and engravers, even though the designs may be supplied by outside artists. Postcard size 4 x 6