Law passed by Congress that allowed the sales of land in the Northwest Territory and all of Northern America
Law passed by Congress that allowed the sales of land in the Northwest Territory and set up standards for land sale that became precedents. Among them was the idea of selling mile-square sections of land.
Important because it contributed largely to early settlement of these lands, and organization of townships and their borders by creating easily understandable borders that were clear and simple, squares.
Anything else--supplemental info, memory pegs, etc.