Rare and important foundation map of Texas and the southwest, the first issue, stating that Arrowsmith is Hydrographer to H.R.H. the Prince of Wales, rather than to His Majesty.

The map covers the Southwestern United States from the Mississippi River to southern California. It was the first large scale map of the area to record the discoveries of Zebulon Montgomery Pike and Alexander von Humboldt. The map itself was bitterly attacked by Humboldt who accused Arrowsmith - not without some justification - of plagiarism. The work is, however, no mere copy, and is superior to Humboldt's in several areas; most notably the delineation of the Californian coast for which Arrowsmith drew on the surveys made by Captain George Vancouver, and the Hudson Bay Company. Also, the rendering of much of Texas and the environs of the Brazos and Guadalupe rivers are much improved. Martin and Martin add that "by combining the best parts of Humboldt's and Pike's maps and avoiding their errors, and by adding his own new information, Arrowsmith contributed a significantly improved depiction of the region".

The present example depicts the boundary of the Texas-Louisiana border along the Mermeto River and follows the official Spanish position as reported by Humboldt, beginning "about a hundred miles east of the mouth of the Salinas, or well into Louisiana, at the mouth of what is called the Mermento River, and then runs northeast along that river and then northwest to only a little above the 32nd parallel, and then runs slightly south of west, with San Saba around 100 miles beyond the boundary" (Streeter 1046D). Later, a second state was issued showing an altered border moved further west and north running along the Sabine and Red Rivers, as accepted by both the United States and Spain in the Adam-Onis Treaty of 1819. The insets are: Valley of Mexico from Mr. Humboldt's Map; Vera Cruz; and Acapulco.

Aaron Arrowsmith (1750-1823) was the finest cartographer of his generation. Although he received little formal education it is believed that he was taught some mathematical instruction by William Emerson, author of several books on the application of mathematics to the area of cartography. Around 1770, Arrowsmith moved to London to seek employment. It is believed that he worked for William Faden before joining John Cary Sr. in the early 1780s. There he provided the measurements for John Cary's early publication detailing the roads from London to Falmouth, his first signed work. Arrowsmith set up on his own in 1790 and over the next thirty years produced some of the most beautiful and elegant maps of the era.