What sparked the California Gold Rush in 1849?

The California Gold Rush was indeed sparked by the discovery of gold at Sutter's Mill near Sacramento in 1848. This major event drew thousands of prospectors and settlers to California in search of wealth, significantly impacting the state's population and economy. The gold was discovered by James W. Marshall while he was working at John Sutter's mill, and news of the discovery spread rapidly, leading to a massive influx of people—often referred to as the "Forty-Niners"—who traveled to California in hopes of striking it rich. This event ultimately resulted in California's rapid admission to the Union as a state and had profound effects on American history, including changes in migration patterns and economic development.

Other choices do not directly relate to the initial cause of the Gold Rush. The signing of the Treaty of Guadalupe Hidalgo ended the Mexican-American War but was not the trigger for the Gold Rush. The Homestead Act, which provided for the distribution of land to settlers, was legislated in 1862, well after the Gold Rush had begun. The establishment of the Pony Express was related to communication across the vast distances of the western territories but also occurred during a different context and did not initiate the Gold Rush itself.