A very rare map of the North American continent published in John Pinkerton’s 1818 American edition of his famous Atlas. Pinkerton’s Atlas was originally published in 1813 and then re-issued in 1818 when the United States and Britain signed the Convention of 1818.  This Convention set the 49th parallel as the Western boundary between British North America and the United States, with the territory west of the Rocky Mountains yet unresolved until the Oregon Treaty of 1846.
It has been argued that the Convention “serves as an example of improved relations between the United States and Britain following the War of 1812.”  As such, the Convention of 1818 helped settle some of the thorny boundary disputes between the two nations following the American Revolution and the Treaty of Paris in 1783.
It is of particular interest that Pinkerton’s 1818 depiction of the Western  boundary is coloured at or near the 50th parallel as opposed to an inconclusive drawing in his 1813 state.  Furthermore, the border West of the Rockies is distinctively drawn to the South of the 49th parallel reflecting, as already mentioned, the agreement within the Convention of 1818 that the area west of the Rockies was to remain “free and open” for a period of 10 years.
Pinkerton’s 1818 map, as opposed to the 1813 edition, is also of interest in the different  depiction rendered for Spanish claims to North America.  Whereas the 1813 state omits completely the Louisiana Purchase and draws all lands west of the Mississippi belonging to Spain, the 1818 map is more restrictive in the depiction of Spanish claims.  The Spanish claims are now only depicted west of the Red River and south of the 40th parallel.
It should be mentioned that the 1818 map continues to depict Florida as a Spanish colony.  Spain would relinquish, the following year, its claims to Florida to the United States following the signing of the Adams-Onis Treaty.
Pinkerton’s rare map of North America from his 1818 American edition is of interest to collectors and historians alike in that it  provides a good example of the fluidity of the boundaries between the United States, British North America and Spain following the war of 1812, on one hand, and the attempts by theses powers to solidify their claims for the future. 
(Sources: The Canadian Encyclopedia. The Convention of 1818)