In 1862, far from the bloodied fields of Virginia and Tennessee, the Civil War raged in the desert Southwest. General Henry Hopkins Sibley marched what became the Army of New Mexico across the Texas Trans-Pecos to Fort Bliss. Driving north into the Mesilla Valley, Sibley hoped to overrun the Union's Fort Craig, push up the Rio Grande, seize the supply depot at Albuquerque, raise the Stars and Bars over Santa Fe, and march on Fort Union, another vital supply depot and the gateway to Colorado. The ultimate objective of the campaign purportedly was the eventual conquest of California, since a continental Confederate States of America stretching from Richmond to San Francisco might well speed diplomatic recognition by Great Britain and France, a vital necessity for the independence of the infant southern republic. The Civil War in West Texas and New Mexico provides new details of Sibley's grandiose and ill-fated dreams for a Confederate empire in the Southwest. Of the 147 letters in the letterbook, only eight have been published in the Official Records. In particular, the letters show how Sibley organized his small army, enlisted officers at the brigade and regimental levels, and sought to supply it with arms and equipment. In addition, as many as 150 individuals, many of them well known, are named in the letterbook. This new study makes for important reading for anyone interested in the Civil War.