Unit 1 California By Li Jinhong Sep 2, 600 Native Americans were living in California. Sep 2, 1600 Native American The Native Americans suffered a lot afrer the settlement of European. Sep 2, 1821 California became part of Mexico. Sep 2, 1846 The United States declared war to Mexico Sep 2, 1848 Gold was discovered in California Sep 2, 1850 California elected to become the thirty-first federal state of the US.