Gold Discovered at Sutter's Mill — California Gold Rush Begins

Nine days before the Treaty of Guadalupe Hidalgo was signed, James Marshall discovered gold at Sutter's Mill in the Sierra Nevada foothills of California — the future American territory. The discovery, kept quiet for months, triggered the California Gold Rush of 1849, bringing 300,000 migrants to California and accelerating statehood. The gold discovery dramatically validated the acquisition of California and transformed the debate over the war's legacy.