The Panama Pacific Exposition Commemorative dollars was one of a group of 5 coins minted in 1915 to mark the celebration of the opening of the Panama Canal. The Exposition was held in San Francisco, which was recovering from the 1906 earthquake and fire. In addition to the Gold dollar there was a silver half dollar and Gold $2.50 pieces of standard size and weight for the denomination and a pair of massive $50 gold piece in both round and hexigonical format (these coins are discussed elsewhere).
All five coins were authorized by an act of Congress on January 16, 1915. The Gold Dollar was limited to a mintage of 25,000 pieces. Eventually 25,034 pieces were struck (with 34 being held for assay) but only a fraction of this number were eventually sold. In late 1916 10,034 coins were returned to the San Francisco Mint and melted on 30 October leaving a net mintage of 15,000.
This coin was designed by Charles Keck. The obverse design is dominated by a left facing portrait of a man wearing a billed cap. The designer claimed that this portrait represented a canal worker. The inscription "UNITED STATES OF AMERICA" arcs along the left side of the coin in two lines of text, from a little before 7 O’clock to a little past 12 O’clock. The date “1915” appears at the bottom under the workers chin.
The reverse shows a pair of stylized dolphins chasing each other around the inscription "ONE DOLLAR" in two lines of text in the center of the coin. Around the outer edge of the coin are the inscriptions "PANAMA PACIFIC EXPOSITION" and "SAN FRANCISCO" with words separated by dots. The "S" mint mark is slightly off center to the left under and between the "D" & "O" of DOLLAR.