Land Measurement

Linear Measurement:
Square Measurement:
1 link = 7.92 inches 9 square feet = 1 square yard
25 links = 1 rod
16 square rods = 1 square chain
1 rod = 16.5 feet 1 square chain = 4,356 square feet
100 links = 1 chain
10 square chains = 1 acre
4 rods = 1 chain
160 square rods = 1 acre
1 chain = 66 feet 4,840 square yards = 1 acre
320 rods = 1 mile
1 square mile = 1 section
80 chains = 1 mile
640 acres = 1 square mile

36 square miles = 1 township

Surveyors divided Illinois into 36-square-mile townships that were located west of the 2nd Principal Meridian or east or west of the 3rd or 4th Principal Meridian. Townships were also located either north or south of base lines that served as latitudinal reference points for each longitudinal meridian. The legal description of a township was expressed in the form of "Township 16N, Range 5W" for example. The Township designation provided the number of the township north (N) or south (S) of the base line, and the Range designation provided the number of the township east (E) or west (W) of a given meridian.

Counties, Townships, and Ranges in Illinois

Each township consisted of thirty-six sections of 640 acres each. Each section included four quarter sections, eight half-quarter sections, and sixteen quarter-quarter sections, each described by a series of directional indicators.

Sections in a Township: Divisions of a Section:

Map and graphics courtesy of Barbara S. Heflin, Illinois State Archives, Springfield, IL.