Copperopolis is a town in California’s Sierra foothills. It was established in 1860 after Hiram Hughes discovered copper ore at Gopher Ridge and the Napoleon Mine. The town grew as more claims, including the Union Copper Claim and Keystone Claim, were developed in the Copper Cañon Mining District. By 1861, the settlement was named Copperopolis, reflecting its focus on copper production.
The town’s first major growth happened during the Civil War, when copper was needed for munitions. Copperopolis became the second-largest copper district in the United States. There were over 28 businesses by 1861 and more than 90 by the mid-1860s. Streets and buildings, such as Union Street and the Union Hotel, showed support for the Union during this period.
A fire in 1867 and changes in copper prices affected the town, but mining continued at different times into the early 20th century. New smelters and better transportation allowed ore to be shipped to Stockton, San Francisco, and other markets. Mining activity continued off and on through the 1930s and during World War II. The Keystone Mine operated until 1945…