Following the Gadsden Purchase, the United States Army sent Major Enoch Steen and four companies of the 1st U. S. Dragoons (now the 1st U. S. Cavalry) to occupy the former site of the Mexican Presidio de Calabasas. Major Steen arrived on November 27, 1856, and named his post Camp Moore. The dragoons put roofs on the old adobe structures and added a few new ones. Camp Moore was abandoned in March 1857 after another location in the San Rafael Valley was chosen for a permanent fort that was christened Fort Buchanan. With the coming of the American Civil War all military posts in western New Mexico Territory (now Arizona) were abandoned. Old Camp Moore at Calabasas was briefly occupied by the Confederates in March 1862, just before the arrival of the California Column in April. The California