Hi Bob;
This goes back about 30 years for me also! A "link" was specified as
6.6 inches in length with 100 links thus making a "chain" of 66 feet.
80 chains thus measured 5,280 feet which is still our standard for a
mile. (If memory serves, a rod is a 1/4 of a chain = 16.5 ft.)
The western states were surveyed in this manner, being gridded into 36
sections (6x6) per Township/Range combination, with each section
theorecticaly being a square with each side measuring 80 chains. A
section ideally contained 640 acres with each acre being 43,560 sq. ft.
The Earth's curvature created some interesting problems for the General
Land Office contract surveyors of those days in order to compensate for
square grids imposed on a gradually curving surface.
Incidentally, the word Township as used in the west has none of the
"political" connotation of the eastern "Town". I first encountered this
while researching in VT and CT and I have since benefited from several
"online" discussions about the political and geographical nature of
Towns in the east.
Hope this cleared more than it muddied!
Bill Harvey (in N. Calif.)
wlh@foothill.net