when did california became part of the union
California What is now California was first settled by various Native American 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.
List of counties in California The state of California is divided into 58 counties.[1] The region was first divided into twenty-seven counties on February 18, 1850. These were further sub-divided to form sixteen additional counties by 1860. Another fourteen were counties formed through further sub-division from 1861 to 1893. The last, Imperial County, was formed in 1907. California is home to San Bernardino County, the largest county in the contiguous United States, as well as Los Angeles County, the most populous county in the United States.