What is the primary unit of the rectangular survey system called?

The primary unit of the rectangular survey system is the township. In this system, townships are used as a fundamental building block for land descriptions. Each township typically measures six miles on each side, encompassing an area of 36 square miles. Within each township, land is further divided into sections, which are each one square mile in area.

Understanding the structure of the rectangular survey system is crucial for interpreting land descriptions and understanding property boundaries in the United States. The township serves not only as the largest unit but also as the reference point from which sections are identified. Each section within a township is numbered, allowing for precise location and mapping of land parcels.

While sections and quarter sections are important subdivisions of land in this system, they are subordinate to the township. Similarly, a subdivision refers to specific divisions of land, often in urban planning contexts, but does not serve as the primary unit of the rectangular survey system.