The document summarizes the history of California's transition from a Mexican territory to a state during the California Gold Rush in the late 1840s. It describes how James Marshall discovered gold at Sutter's sawmill in 1848, sparking the mass migration of people to California seeking fortune. Over 100,000 people immigrated to California in 1849 alone. The document also discusses how California became a state in 1850, though Native Americans and others were denied basic rights and many Native American tribes were wiped out by violence and disease during this period.