Senex's map is one of the earliest large-scale English maps of North America. 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.
One of the most remarkable large format English maps of the period, embellished with a large cartouche and coat of arms.
The map has 5 currently recognized states:
- Stevens & Tree 61a. "By John Senex, Cha. Price & John Maxwell, Geographers 1710".
- Unrecorded state. "By John Senex and John Maxwell Geographers 1710".
- Stevens & Tree 61a*. "By John Senex F. R. S. 1710". Price & Maxwell's name deleted from the title. No Imprint beneath the scales in the bottom left corner. (1710)
- Stevens & Tree 61b. "By John Senex F. R. S. 1710". Price & Maxwell's name deleted from the title. Imprint added, "Printed for T. Bowles 1710." (1710)
- Stevens & Tree 61c. Includes the imprint of T. Bowles, J. Bowles & Robert Sayer. [1750 ca]
John Senex (1678-1740) was one of the foremost mapmakers in England in the early eighteenth century. He was also a surveyor, globemaker, and geographer. As a young man, he was apprenticed to Robert Clavell, a bookseller. He worked with several mapmakers over the course of his career, including Jeremiah Seller and Charles Price. In 1728, Senex was elected as a Fellow of the Royal Society, a rarity for mapmakers. The Fellowship reflects his career-long association as engraver to the Society and publisher of maps by Edmund Halley, among other luminaries. He is best known for his English Atlas (1714), which remained in print until the 1760s. After his death in 1740 his widow, Mary, carried on the business until 1755. Thereafter, his stock was acquired by William Herbert and Robert Sayer (maps) and James Ferguson (globes).