when did california become part of the us
California What is now California was first settled by various Native Californian tribes before being explored by a number of European expeditions during the 16th and 17th centuries. The Spanish Empire then claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its successful war for independence but was ceded to the United States in 1848 after the Mexican–American War. The western portion of Alta California then was organized and admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom.
San Diego San Diego has been called "the birthplace of California".[13] Historically home to the Kumeyaay people, it was the first site visited by Europeans on what is now the West Coast of the United States. Upon landing in San Diego Bay in 1542, Juan Rodríguez Cabrillo claimed the area for Spain, forming the basis for the settlement of Alta California 200 years later. The Presidio and Mission San Diego de Alcalá, founded in 1769, formed the first European settlement in what is now California. In 1821, San Diego became part of the newly independent Mexico, which reformed as the First Mexican Republic two years later. California became part of the United States in 1848 following the Mexican–American War and was admitted to the union as a state in 1850.