Who brought thousands of people to California in the late 1800s?

In the late 1800s, thousands of people were brought to California primarily due to the Gold Rush, which began in 1848. This influx was spurred by news of gold discoveries at places like Sutter's Mill, attracting fortune seekers from across the United States and around the world. Additionally, the completion of the Transcontinental Railroad in 1869 made travel to California more accessible, further increasing the population. Prominent figures, such as John Sutter, who initially discovered gold, played significant roles in drawing people to the region.