Captain Pittman was an engineer in the British army when he was assigned to a unit that sailed up the Mississippi River about 1763 to take possession of French military posts in Illinois country, after the conclusion of the French and Indian war. He also described Spanish towns and posts on the lower Mississippi, on the way north. This is was the first English report of these Mississippi towns in Illinois.

Pittman’s plans and maps of several of the locations are at the back of the volume, including a plan of Kaskaskia and maps of the Mississippi.