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The Hercules Powder Works

Before becoming the site of the Hercules Works, Refugio Valley was a province of Pinole, a 19th Century agricultural hinterland of San Francisco. In 1878 the Northern Railway arrived, and lands of the lower Refugio Valley were first acquired by California Powder Works. In the years leading up to the Civil War, California industrialists had founded the California Powder Works in Santa Cruz to assure the supply of black powder explosives for mining and construction. Hercules Works in the Refugio Valley was to produce the new high-order explosives, and a range of explosive and other chemicals over the next century. 

The California Powder Works purchased a 44.94-acre portion of Rancho El Pinole from the Martinez heirs in 1879. Subsequent purchases increased the site to about 3,000 acres, extending two miles up Refugio Valley. By 1881 the first acid plants were feeding nitroglycerine production lines. In less than twenty years, under the direction of Captain William Russell Quinan, the Hercules plant would become the largest in the world, producing more than half the dynamite made on the West Coast. In World War I, it was the largest TNT plant in America. 

Hercules was the brand name of a product, dynamite. High volume manufacture of dynamite was pioneered in the Refugio Valley by the men of California Powder Works. This place, a center of innovation in chemical engineering, came to be named Hercules, after the brand name for dynamite sold worldwide. Hercules Powder Company was entwined in ownership with the monoplist E.I. duPont de Nemours; both were involved in early antitrust actions under the Sherman Act.

The explosive products made here and the techniques of their production were profoundly important to society. Explosive chemicals were fundamental to the rise of large-scale industrial production that lifted living standards and transformed societies. Powerful chemical explosives shaped the world in which we live today.