Scott #400 and #400A (color variant): 10¢ “Discovery of San Francisco Bay” is the final stamp in our series on the Panama-Pacific Exposition series of stamps published in 1913. Of the 4 stamps in the series, it has the most interesting philatelic history. Scott #400 was the fourth stamp in the series and was issued January 1, 1913. Soon after publication, however, complaints from the public started coming into the Postal Service that the orange color was to light and the fine detail of the illustration was lost.
Plans were made by the Postal Service to reissue the stamp with a darker shade of orange. On August 25, 1913 – 7 months after it went on sale – #400 was removed from sale and all remaining quantities were destroyed. A darker version was issued in its place, and given the number 400A. The alternate color version of the stamp was not considered at the time a separate variety by the Postal Service and many collectors did not acquire as many copies – the darker version (400a), therefore, commands a higher price than the original.
This, however, was not the end of the story for this stamp. The Postal Service also had increasing complaints about a different problem. High-volume mailers were complaining about problems with separating stamp sheets with 12 perforations, like #400/400a. They said that they were too brittle and fell apart too easily. The Postal Service, therefore, made a change and went to 10 perforations per 2-centimeters making the sheets stronger. The Panama-Pacific stamps were the first to be altered to the 10 perforations. In July 1915, the third version of the .10-cent stamp was issued (Scott 404). Of the 3-variations of this design, this stamp is the highest value.
The design depicts the discovery of San Francisco Bay by Spanish explorer, Gaspar de Portola. Great navigators, such as Juan Rodriguez Cabrillo, Sir Francis Drake and Sebastián Cermeño explored the coastline near San Francisco Bay, but failed to discover this waterway probably because of the fog. It took an overland explorer to be the first European to see the beautiful San Francisco Bay. On November 4, 1769, de Portola glimpsed the bay from atop Sweeney Ridge near present-day Pacifica. The design is based on a painting by Charles F. Mathews, the image was engraved by M. W. Baldwin.