A state of the western United States on the Pacific Ocean. It was admitted as the 31st state in 1850. The area was colonized by the Spanish and formally ceded to the United States by the Treaty of Guadalupe Hidalgo (1848). California is often called the "Golden State" because of its sunny climate and the discovery of gold during its pioneering days. Sacramento is the capital and Los Angeles the largest city. Population: 35,400,000.