California is a state located on the West Coast of the United States. It is the most populous U.S. state, home to one out of eight people who live in the U.S., with a total of 38 million people, and it is the third largest state by area . California is bordered by Oregon to the north, Nevada to the east, Arizona to the southeast, and the Mexican state of Baja California to the south. It is home to the nation's second and fifth most populous census statistical areas , and eight of the nation's 50 most populated cities . Sacramento is the state capital, and has been since1854.What is now California was first settled by various Native American tribes before being explored by a number of European expeditions throughout the 16th and 17th centuries. It was then claimed by the Spanish Empire as part of Alta California in the larger territory of New Spain. Alta California became a part of Mexico in 1821 following its successful war for independence, but would later be ceded to the United States in 1848 after the Mexican-American War. The western portion of Alta California was soon organized as the State of California, which was admitted as the 31st state on September 9, 1850.