Following the Treaty of Paris in 1763 which ended the French and Indian War Britain gained possession of all the territory west to the Mississippi River. The 34th Regiment was dispatched to the recently acquired Illinois region in late 1765 to demand the surrender of the last French outpost in the region at Fort Chartres. As the title indicates Lieutenant John Ross, surveyor with the Regiment, undertook a survey of this new territory. In addition to his own surveys, Ross also drew on French sources, especially the maps of Jean Baptiste d’Anville. This is the FIRST LARGE SCALE ENGLISH MAP OF THE REGION PUBLISHED AFTER THE TREATY. It extends northwards to the region just south of present day St. Louis. Indeed, the area just south of the Ohio River is the New Madrid region which 36 years later between 16 December 1811 and 7 February 1812 would be devastated by four magnitude 8 earthquakes which wiped out the town and altered the course of the Mississippi River. It is one of the more significant and important maps published at the time as it records for the first time the new territories gained by the British in the west which encouraged migration to the area. It would also mark the western boundary of the future United States of America.

The map is full of regional information noting local tribes, numerous towns and forts and even mines, quarries and cane fields! There are brief legends throughout which are more descriptive including points of interest such as the site of De Soto’s discovery of the Mississippi River in 1541 and navigational instructions. This map was first published in 1772 and this state was issued for the first edition of Thomas Jeffery’s ‘American Atlas’. It bore numerous improvements particularly in the region of New Orleans in the lower Mississippi. Forts T. Lion and St. Mary were added. This lower region is outlined green to indicate its retention by the French although Baton Rouge is shown to the north. Lemmon, Magill & Wiese (2003) pp. 106-7; Phillips (1901) p. 439. Phillips (1909-) 1165; Sellers & Van Ee (1981) 781; Shirley (2004) T.Say 2b no. 33; Stevens & Tree (1967) 31 state b.