California is divided into 58 counties. 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 though 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.