This map is entitled, "A plan of Kennebek & Sagadahok rivers, with the adjacent coasts taken from actual surveys and dedicated to his Excel. William Shirley Esqr."

The map has illustrations of Fort Frankfort, Fort Western, Fort Halifax and Fort Frederick, with accompanying explanatory material.

Created around 1754 by Johnston, it was used in litigation between the early land grant proprietorships of Maine: The Plymouth Company and the Proprietors of the Township of Brunswick.