This ‘Map of the United States of North America…’ is from David H. Burr’s (1803-1875) ‘American Atlas’. Wheat called it ‘in every respect a towering example especially in the Far West, and it is strange that it should be so rare!’ The source material is Jedediah Smith’s original map. This example is likely to date to 1842 based on internal evidence despite the fact that the plate itself had not altered since 1839. This is indicated by the nature of the colouring of the Maine boundary, the additional counties that have been identified in Michigan and the development of the railways. The boundary of Oregon and Canada in 1846 is almost certainly a later addition as the red is darker than elsewhere. Most surviving example are dissected in four, this one is in eighths. This so called ‘atlas’ is of remarkable rarity. The plates themselves were engraved in London by John Arrowsmith which by then was an unusual occurrence. American mapmakers were largely independent of British input by then. Phillips 4525,1379a note; Sabin 9438; Streeter 3859; Wheat 441.