Rare index to accompany Le Rogue's copy of Mitchell's seminal map of America.

Mitchell's map is widely regarded as the most important map in American history. Prepared on the eve of the Seven Years' War (or French and Indian War), it was the second large format map of North America printed by the British (the first being Henry Popple's map of 1733), and included the most up to date information of the region: "the result of a uniquely successful solicitation of information from the colonies" (Edney). Over the following two hundred years, it would play a significant role in the resolution of every significant dispute involving the northern border of the then British Colonies and in the definition of the borders of the new United States of America, at the Treaty of Paris.

Le Rouge published his example in 1777, just two years into the War of Independence. Le Rouge faithfully copies Mitchell's original, however to the border, he has added numbers and letters to the x and y axis in order to aid location. The catalogue here, provides a list of all the place names on the map together with their grid reference. An advert on the verso of the title page gives instruction in how to use the grid references.

The catalogue is extremely rare with only one other known institutional example: The Bibliotheque Nationale Paris.