What is the N-S axis referred to in establishing an initial point in a government land survey?

In the context of government land surveys, the N-S (North-South) axis is referred to as the principal meridian. The principal meridian serves as the primary reference line for establishing land boundaries and coordinates in a specific area. It runs vertically from the North Pole to the South Pole and is integral to the Public Land Survey System (PLSS) used in many parts of the United States, including Wisconsin.

The principal meridian helps define townships and sections, which are fundamental units in land measurement. Each principal meridian is associated with a specific region and is paired with a baseline (which runs East-West) to create a grid system for surveying land. This system is critical in ensuring that land is accurately divided and can be uniformly referenced.

While other terms like base line, section line, and line of latitude are pertinent to surveying and mapping, they serve different purposes. The base line, for instance, is a horizontal reference from which measurements are taken, while section lines refer to divisions within a township. A line of latitude is a geographical reference that indicates the position north or south of the equator but does not pertain to the government land survey framework in the same manner as the principal meridian. Therefore, understanding the role of the