Chain (unit) - Wikipedia
Linear Measurement
1 Chain = 100 links or 66 feet
1 Mile = 80 chains or 5,280 feet
Area Measurement
1 Acre = 10 square chains or 43,560 square feet
1 square mile = 640 acres
— Lola Cazier (1976), Surveys and Surveyors of the Public Domain 1785-1975, page 15
