Highly detailed map of the United States, illustrating a number of the transitional Trans-Mississippi West territorial boundaries on the eve of the Civil War. Washington and Oregon Territories extend from the Pacific to the Rocky Mountains. Utah and New Mexico Territories extend from California to the Rocky Mountains. Arizona appears in a very curious configuration south of the Gila River only. Kanzas Territory extens from Missouri to the Rocky Mountains. Nebraska Territory runs from Kansas to the Rockies and the Canadian Border. Misshapen Texas, with exellent detail. Nice detail in the Colorado region, on the eve of its becoming a territory. Excellent detail throughout the Transmississippi West.