The maps prepared by the Massachusetts and Maine Land Offices, or accumulated by those agencies, represent various surveys and lottings of boundary lines since the 1700s. From time to time, the Maine Legislature authorized funds for copying of early maps of Maine held by Massachusetts for the benefit of the Land Office. These maps show the division of lands among settlers and establishment of boundary lines between Massachusetts, Maine, and Canada. Includes topographical descriptions and survey notes on the quality and quantity of timber and land.

The abbreviation WELS refers to "West of the Easterly Line of the State," the north-south line from Hamlin to Amity in Aroostook County.

BKP refers to "[William] Bingham's Kennebec Purchase," and BPP is "Bingham's Penobscot Purchase." The Schoodic River is now known as the St. Croix River.