After the Civil War, Americans began settling the vast western territories. The Great Plains had little rainfall and supported vast buffalo herds that Native Americans depended on. By 1900, the buffalo were wiped out as the land was settled by miners, ranchers, and farmers, devastating Native American communities. Western settlement was driven by gold and silver rushes that began in California in 1848 and stimulated economic growth. However, it also led to conflicts with Native Americans over land and exclusion of Chinese immigrants. The Homestead Act of 1862 encouraged family farming but many failed due to harsh conditions. By the late 1800s, the American frontier was declared closed as the last lands were settled.