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Imaginary lines used in the rectangular survey land description system to describe land location.


Meridians are imaginary lines that are used as a reference point when measuring land using the rectangular survey system. The specifics of a the rectangular survey system and its use of meridians can be found below. A meridian line connects the North and South Pole by equal latitudes. The meridian line helps one understand how far and how many degrees the equator is from a specific point.

The rectangular survey system, also known as public land survey system, is the primary land measurement system used by the government to define public land. The system may also be referred to as the section and township system or U.S. government survey system. Regardless of what the system is named, the U.S. Surveyor General is tasked with measuring public land and defining public and private boundaries for the government.

How Land is Measured Using the Rectangular Survey System

The rectangular survey system measures land using square miles as a basis for description. A unit of land is almost 24 square miles. The boundaries form base lines that run east and west, while the guide meridian runs north and south. The 24-mile square area is split into six square mile portions of land called townships. The six-square mile township is then divided into 36 sections, each equivalent to one square mile. A physical marker is typically installed into the ground to indicate the presence of a boundary. Survey descriptions use compass points. Compass points are labeled first using the smallest area and then the largest area.

Measurement of land using this system begins with a starting point, whereby the rest of the survey is based on. The starting point is the area used where the longitude and latitude of the land will be determined. The initial point is then used to define the principal meridian which runs north and south with a base line that runs east and west. The meridian and base lines essentially run perpendicular to each other as they cross paths. The six square mile points are marked as strips of land that are six miles wide and are numbered from east and west of the meridian. This means the first township that is north of the base line and east of the meridian is labeled as Township 1 North, Range 1 East, and the proceeding townships are labeled as North 2 and East 2, or North 3 and East 3.

Correction Lines and Measuring Land

The earth’s natural curvature does not allow an equal system where all townships are parallel to each other. To address this issue, the general surveyor utilizes a correction line between every four townships to properly establish boundaries. The difficulties with this system include the fact that property shapes are irregular and physical features change over time, making it very difficult to accurately measure land.

History of Rectangular Land Measurement System

The rectangular survey system was created in 1785 through the Land Ordinance of 1785. The idea of the measurement system was originally proposed by Thomas Jefferson after the revolutionary war. Knowing that after the war the government would be responsible to divide newly acquired land amongst soldiers and private citizens, the United States implemented Jefferson’s suggestion. After the passage of Northwest Ordinance of 1787, land began being divided to private citizens using this land measurement system.