The Public Land Survey System (PLSS) organized land in the US into townships, ranges, and sections, each with a specific number of acres. A township is a square area 6 miles on each side, containing 36 sections of 1 square mile each (640 acres). A range is a row of townships, and a section is a square area within a township, typically comprising 640 acres. These entities allowed for easy surveying, subdivision, and identification of land, facilitating land grants, homesteading, and the expansion of the US westward.
