One of the earliest large-scale English maps of North America, incorporating the best available French and English sources.

The map represents a British attempt to consolidate new information about the region and borrows data from such recently published sources as Delisle's landmark Carte du Mexique et de la Floride and Carte de la Canada. Senex improves upon this work with a fine depiction of the Great Lakes region and the most accurate definition of the lower Mississippi River and its delta by an English cartographer of the period.

Several of the most important and controversial cartographic discoveries of the period are discussed at length, including Lahontan's mythical Long River and the Salt Lake east of the Country of the Mozeemleck's, both of which are also depicted in remarkable (albeit fanciful) detail.

Sir William Phipps's discovery of Spanish wrecks off the coast of the Caicos and Southern Bahamas is noted. Senex also extended the map's coverage to the Canadian Arctic and the Terra Incognita above Baffin's Bay. Present-day Oklahoma and Texas are part of La Floride, considered at the time to be a possession of the French. The Red River and the Indian villages of east Texas are portrayed accurately, but Senex, following Delisle, incorrectly placed many Texas rivers, in addition to depicting some strange and unrecognizable names.

The map has 5 currently recognized states: