For stamp collectors, the 1915 Panama-Pacific Exposition in San Francisco, Calif., was one of the many large fairs that resulted in a set of new United States postage stamps.
The first day of the exposition was 100 years ago, on Feb. 20, 1915, and it ran until Dec. 4, 1915.
Four designs were developed and printed to commemorate the exposition, but in all there are nine stamps in the set.
In January 1913, the 1¢ green Vasco Nunez de Balboa, the 2¢ carmine Pedro Miguel Locks, the 5¢ blue Golden Gate and the 10¢ orange yellow Discovery of San Francisco Bay stamps were issued (Scott 397-400). An orange color variety of the 10¢ stamp was created several months later (400A). All five stamps were perforated gauge 12.
From December 1914 to July 1915, a new group of four stamps, perforated gauge 10, was issued, with the 10¢ stamp in orange (Scott 401-404).
Collectors particularly treasure these stamps found on cover, struck with one of the 1915 exposition cancels.
The stamps were designed by Clair Aubrey Huston, who also designed the 1904 stamps for the Louisiana Purchase Exposition (Scott 323-327) and the 1907 stamps for the Jamestown Exposition (328-330).
The city of San Francisco and the San Francisco Public Library is commemorating the 100th anniversary of the exposition with pictorial postmarks dated Feb. 20 and Feb. 21. Both postmarks show the same design of the rotunda of the Palace of Fine Arts, and original structure from the exposition that stands today as part of the city's Palace of Fine Arts Theatre.
To obtain an example of the postmark, send an addressed stamped envelope to San Francisco Public Library Station, Postmaster, 100 Larkin St., San Francisco, CA 94102. Requests should be postmarked no later than March 18.