This map by McMurray was only the second American map to depict the new nation. It may be read as an implicit declaration of sovereignty over the national territory, at a time when this existed on paper only. For example, McMurray shows the Old Northwest divided into ten as-of-yet unnamed states, though there were few Americans there and the British still held key posts. More striking still is the failure to depict any native American presence between the Appalachians and the Mississippi, though they remained the dominant force in the region.
A former assistant to Geographer of the United States Thomas Hutchins, McMurray used unpublished surveys made for the Continental Army to compile a detailed depiction of the eastern part of the country. For the trans-Appalachian region he relied on published sources, notably Hutchins’ New Map of the Western Parts of Virginia, Pennsylvania, Maryland, and North Carolina (1778) and, for the region west of the Great Lakes, Jonathan Carver’s Plan of Captain Carver’s Travels in the Interior Parts of North America (1778).
It is worth comparing McMurray’s map with a contemporary British map of the United States, such as item 2b below.