By: Jules Marcou
Date: 1853 (dated) Boston
Dimensions: 22 x 31 inches (56 x 78.75 cm)
A rare variant of an already scarce and early geologic map of the United States.
This map by Jules Marcou, most commonly found as a folding, backed with linen and attached to a pocket folder, came to us printed on two separate sheets with one centerfold, intended for a large book or atlas.
Examining the Map
Marcou's map centers on the Midwest and extends from the eastern seaboard, from the Florida Keys to southern New Foundland, to the Texas - Mexico border and the Rocky Mountains. The map is color-coded by the underlying geology with rock types falling under four main categories, Modern, Secondary, Paleozoic, and Eruptive / Metamorphic Rocks. Two cross sections appear atop and to the left of the map. These correspond with linear lines found in the map that connect Yorktown, Virginia with Fort Laramie, Wyoming at the base of the Rocky Mountains, and Lake St. John, Canada to Mobile, Alabama (the Gulf of Mexico), by way of Nashville, Tennessee.
Additional surface cartography located important cities of the era, along with some of the early military forts and outposts on the western Frontier such as Fort Union, Fort Laramie, Bents Fort, Fort Mann, and Fort Towson, to name a few. These forts were in a volatile state of peace and war with the indigenous plains tribes of which less than half are recognized; the Arrickera, Assinaboin, Mandan, Sioux or Dacatoah, Arapahoe, and Cheyenne. One interesting note that is not often found in maps of the frontier is an area just south of the Bad Lands that labeled "Indian Enchanted Ground," which is now the approximate location of Mount Rushmore.
Controversy and Criticism of Marcou's Work
Marcou's geologic map of the United States was widely regarded both then and now as ambitious with regards to not only the vast territory he provides geologic information on, which was still a largely unknown on the surface, but also some of the early scientific assumptions and conclusions he presents. According to Jules Marcou, the information on display in his map was garnered by all the public documents and manuscript ones relating to the subject and then verified through three years of extensive travel throughout various parts of America.
While Marcou claimed to have been assisted by American geologists, he was later criticized for his lack discretion and his scientific generalizations. One piece of criticism found in the 1904 Report of National Museum states that Jules Marcou's map was "commendable, requiring courage as well as judgement. Unfortunately, Marcou does not seem to have used discretion in all cases in the selection of his authorities, and made altogether too sweeping generalizations , often in direct contradiction of facts made known by the other workers." Source
Condition: Map is in B condition, with lovely hand coloring over a dark print impression and ample margins on all sizes. Some damp-staining and foxing is apparent but does not distract from the overall eye-appeal of the work.
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