Rare first state of Charles Desilver's map of the West, predating the change in decorative borders in 1856.
From 1846-1851, Mitchell and later Thomas Cowperthwait & Co., used the same basic copper plate for the map of Oregon and Upper California, updating the information and later the title on at least an annual basis. In this second state of the map, 2 degrees of the Pacific have been removed and the map shifted east two degrees, to show more of the course of the Yellowstone River, and the regions just east of the Rocky Mountains. The early errors have been corrected and the cartography continues to improve.
In addition to adding counties in vivid color (a few still stretching nearly across the entirety of New Mexico and Utah) the map is updated along the Rio Grande and south of Salt Lake.
Many new trails are added, including Fremont's trails, Kearney, Col Cooke, etc. The Spanish or Los Angeles Route, Oregon Trail and Lewis & Clark Canoe Routes, are still shown. The Gadsden Purchase is now shown, as is the difference between Bartlett's line and Graham's Line, just east of Tucson, which is part of Mexico. Only Tulare and San Bernardino County are now shown. As are Skamania and Walla Wall Counties, east of the Cacades in Washington.
Many other fascinating minor changes. Desilver editions prior to the bramble style border are quite scarce.