The 1915-S Panama-Pacific $2.50 quarter eagle was struck alongside four other commemorative coins honoring the 1915 Panama-Pacific Exposition in San Francisco. The occasion was huge, not only serving as that year's world's fair but also taking place in the city that had less than a decade earlier been ravaged in a massive 1906 earthquake.

The design on the quarter eagle is a collaborative effort between Charles E. Barber and George T. Morgan. The obverse features the goddess Columbia bearing a caduceus and seated on a hippocampus, while the reverse shows a likeness of an American eagle. Many were spent, though the vast majority exist in uncirculated grades ranging from MS62 through MS66, with those grading higher much scarcer.