1761 Brehm, Lt. Dietrich - Chigago River and village, Public Records Office, London.
In 1761 the British military officer Lt. Dietrich Brehm visited Chicago while surveying and mapping the territory newly acquired from the French near the end of the French and Indian War. An excerpt of his map shows the "Chigago River and village," and portrays with fair accuracy the portage, Mud Lake, and the Des Plaines and Illinois rivers.