Gold is discovered at Sutter's Mill in California by James W. Marshall as he sees shining flecks of gold in the tailrace of the sawmill he was building in partnership with John Sutter; The discovery unleashes the California Gold Rush and changed the course of California's and the nation's history.
The migration rapidly transformed the region, boosting the U.S. economy, accelerating California's statehood, and making San Francisco as a major city. The gold rush also caused displacement and harsh conditions for Native Americans. On December 5, 1848, President James K. Polk officially confirmed the discovery of gold during his annual address to Congress, this official confirmation ignited "gold fever" across the nation, leading to the massive migration in 1849. More
First gold nugget found in California starting the Gold Rush of 1849 - Public domain