A nice example of what Carl Wheat called “one of the most beautiful maps ever published by the Army,” a map that “is a landmark map for various regions.” It shows the region around the “four corners” in the American Southwest, based on surveys from an 1860 expedition led by Captain John N. Macomb to explore the Old Spanish Trail from New Mexico towards Utah. The expedition is important in its confirmation that the Green and “Grand” (now Colorado) Rivers joined to form the Colorado just above the Grand Canyon. The map was printed in 1864, but didn’t actually get published until 1875 because of the Civil War.
Wheat’s comments on its importance is not only based on its geographical significance, but also because of its documentation of the routes of various explorer’s routes, including Macomb’s as well as those of Gunnison, Marcy, and Father Escalante and others. The last factor in Wheat’s judgments is it striking appearance, where it looks almost three dimensional. This is the result of a technique of depicting topography developed by F.W. Egloffstein, where his intent was to “give his map the appearance of a small plaster model of the country.” This was achieved by applying very fine lines on the plate by use of a ruling machine (done by Samuel Sartain), which were then exposed to acid to varying degrees to achieve the desired appearance. Only a few maps where made using this difficult process and this is the finest example thereof. The map is a wonderful depiction of the main drainage areas of the American Southwest, as well as many other features such as pueblos, archaeological sites and settlements, all conveyed with a remarkable appearance that few other maps have every matched.