1915-s PANAMA Pacific Old Commem Half Dollar 50c Grades Unc Details. Exceptionally Rare Commemorative. The Pan Pac was Minted Along with 4 Other Coins to Commemorate the Completion of the Panama Canal and Distributed at the Panama Pacific Exposition in San Francisco which also Celebrated the Renewal of San Francisco since the Great Fire. When Examining the Pan Pac Half Dollar, Note that there is a Problem with Pan-Pac Halves in its Strike: Weakness is often Evident on Columbia’s Head, Cap, Arm and Body, also on the Eagle's Breast Feathers and Claws. Occasionally, Coins are seen with a Rim Indentation Near the Periphery on Each Side; this is a Mint Caused Problem and Should Not Be Factored Into the Grade. When Grading Lightly Circulated Examples, Friction is First Evident on Columbia's Shoulder and on the Eagle's Breast.