The field notes, reflecting the method of surveying, are divided into two subseries: interior and exterior notes. Exterior boundaries of townships were surveyed and laid out first; interior section lines within townships were surveyed and marked later. Separate field notebooks were kept for each survey. Hence, two sets of notes must be consulted for each township.
Each notebook has a separate volume number; they are divided into three numbering sequences. There are 139 notebooks for the interior surveys of townships west of the fourth principal meridian (called “interior west notes”), 221 notebooks for the interior surveys of towns east of the fourth principal meridian (called “interior east notes”), and 311 notebooks for the exterior boundary surveys (called “exterior notes”). Two key maps, one for exterior survey notes and one for interior survey notes, show the volume numbers for the notes for each survey township.
The interior notes for any given township are included in a single volume. The exterior notes for a township may be found in as many as four different volumes, with each border of the township in a separate volume.
Researchers using these records will find it necessary to understand the rectangular survey grid system for subdividing and numbering parcels of land. A copy of the Rockford Map Publishing Company's “Important Facts about Land Surveys” is attached. Note that in Wisconsin, townships are numbered as being north of the base line, the Wisconsin-Illinois border, and east or west of the fourth principal meridian, an imaginery north-south line extending from the Illinois border at the junction of Grant and Lafayette counties north to Lake Superior at the Wisconsin-Michigan border.
