The classic gold Commemorative series spans a 23-year period from 1903 through 1926, but it includes only 13 separate issues.  Included in this small number, however, are some of the most popular and enduring of all U.S. coinage designs.  Chief among these are the impressive 1915-S Panama-Pacific $50 pieces in both round and octagonal formats.  The other 11 deliveries in this series are the 1903 Louisiana Purchase Gold Dollars either with Jefferson's or McKinley's portrait, the 1904-1905 Lewis and Clark Exposition Gold Dollars, the Gold Dollar and Quarter Eagle that were also struck in conjunction with the 1915 Panama-Pacific Exposition, the McKinley Memorial Gold Dollars of 1916-1917, the 1922 Grant and Grant with Star Gold Dollars and the 1926 Sesquicentennial Quarter Eagle.