A mysterious US Mint medal series was recently uncovered after being hidden from the public eye for over five decades. These medals were designed and minted by the US Mint in Philadelphia. In all, a total of 9,858 medals were struck. These medals came in 3 sizes: half-dollar (30.6mm), dollar (38.1mm), and medallion (76.0 mm). The half-dollar size medals were struck in .900 fine silver. The dollar size medals were struck in both 18K gold and .900 silver. The medallion size medals were struck in bronze. 17 design variations have been currently identified and cataloged.