Final Answer:
In 1848, a significant event known as the California Gold Rush began at Sutter's Mill. The discovery of gold in the mill's vicinity attracted a massive influx of settlers and fortune-seekers from various parts of the United States and around the world, leading to a substantial westward migration.
Step-by-step explanation:
In January 1848, James W. Marshall, while working at Sutter's Mill in Coloma, California, made a transformative discovery that would alter the course of American history—the finding of gold. This discovery marked the onset of the California Gold Rush, a pivotal event that drew people in unprecedented numbers to the West. News of the gold find spread rapidly, triggering a frenzied rush of prospectors, commonly known as "forty-niners," hoping to strike it rich by panning for gold in the rivers and streams of California.
The allure of potential wealth spurred a massive migration of settlers from the eastern United States and beyond, as well as immigrants from countries worldwide. The California Gold Rush became a defining chapter in American westward expansion, leading to the rapid growth of settlements and the development of California as a state. The transformative impact of the Gold Rush on the demographics, economy, and culture of the region contributed to the shaping of the American West as we know it today. The lure of gold was a powerful force that catalyzed a significant movement of people, marking a crucial chapter in the nation's history of westward migration.