The 1st Regiment California Volunteer Cavalry was a cavalry regiment in the Union Army during the American Civil War. It was first formed of five companies as 1st Battalion, 1st Regiment California Volunteer Cavalry between August and October 31, 1861, at Camp Merchant near Oakland. After the battalion was organized it was sent to Southern California, three companies being stationed at Camp Latham, near Los Angeles, and two at Camp Carleton, near San Bernardino. November 20–29, 1861, a detachment under Second Lt. C. R. Wellman was stationed at Camp Wright, and pursued and captured Dan Showalter's party west of the San Jose Valley and Warner's Ranch. The battalion remained in Southern California until the spring of 1862, when it became part of the California Column, and formed the advance f