This large four sheet wall map of the United States west to the 100th meridian must have been intended to accompany Burr's 1839 thirteen sheet American Atlas of postal wall maps (see our 0104.000), although there is little record of its publishing other than a listing in Phillips Maps of America, p.896. The American Atlas has a large map of the United States from coast to coast, but it lacks the detail of this wall map, which shows all most all of the postal roads, canals, and railroads that are delineated on the large scale individual state maps of the American Atlas. That detail makes this wall map one of the best large area road maps of the United States as a whole, of the period - more detailed than Tanner's Map of the United States or Mitchell's Reference and Distance Map of the United States. Burr likely published it as an addendum to the American Atlas to give a larger overview of the road system of the entire United States. Ristow (p.106) mentions that Burr published an edition of the American Atlas in 1842, so it is likely that this map was added to the set then. We are presuming that John Arrowsmith was the publisher and printer because of the similarity of style between this wall map and the American Atlas which he published for Burr, but his name does not appear on the map. There is no key or legend, only a scale of miles, and only two classes of roads are shown, primary and secondary, compared to four classes of roads shown on the American Atlas state maps. In the lower right corner is an untitled inset map of North and South America that is a slighly simplified version of part of John Arrowsmith's Map of the World on Mercators Projection, 1844 (see our 4613.002), further evidence of the John Arrowsmith involvement in publishing this wall map.