Giant Powder Company. Two shaded ad cover in green of the Giant Powder Co., both from the same correspondence to Jackson, Cal., one franked with 1¢ + 2¢ Bank Note with San Francisco postmark & other franked with 3¢ Bank Note with San Francisco cds, one bit reduced at right & one bit reduced at left, F.-V.F., an attractive & scarce pair. Estimate  $200 - 300. The Giant Powder Company, the first commercial manufacturer of dynamite in the United States, began production in San Francisco on March 19, 1868, under exclusive license from Alfred Nobel to produce his new explosive in America.A year and a half later, on November 26, 1869, an explosion destroyed the entire facility, turning every one of the buildings on the place, and the surrounding fencing, into "hundreds of pieces," according to a newspaper account. The company moved its operations elsewhere, an action that was to be repeated again in the future under similar circumstances, until it moved to its permanent and final home at Point Pinole on San Pablo Bay. $0 (Image)