Early Plat Maps


A Selected DeForest-Times Tribune Newspaper Feature on the Original Survey and the Creation of Plat Maps for the Area (2012)

  • "Area Plat Maps-Beginnings and More" (Word)



by John Englesby

What Are Plat Maps?

A “plat” is simply a defined area or plot of land. A plat map is a representation of a specific plot, typically drawn on flat paper to scale. Plat maps of area townships have always been of high interest to many, especially historians and those interested in early settlements, family homesteads, and genealogy.

Have you ever wondered how and when the township lines were created and who was responsible for drawing and distributing the resulting maps? Read on.

The Original Survey

The land area that is now known as the state of Wisconsin was surveyed by the federal government between 1833 and 1866. It was completed in order to divide the vast public domain of federal land into small lots for sale and management, to raise needed funds for the government, and to encourage settlement in these areas. The surveys could only be conducted on land to which the U. S. government had title. Therefore the process did involve transfers of land titles from some Native American groups.

In the Midwest and most of the Western United States, surveys were completed according to the Public Land Survey System (PLSS), which divided land into six-mile square townships and one-mile square sections within the townships. Like on a sheet of graph paper, the townships were similarly arranged across the state. The land in our area was surveyed in the 1830s.

The survey work was accomplished by the federal General Land Office. Instructions were given to all surveyors engaged in the work. During the three decades that the survey was conducted in Wisconsin, the instructions to the surveyors changed and evolved, but consistency was achieved and the final resulting maps and records were of profound significance.

The Starting Point

The starting point of the public land survey in Wisconsin was on the Wisconsin-Illinois border about 10 miles east of the Mississippi River. This initial point marks the intersection of the baseline (the southern state boundary) and the principal meridian, which is a line that runs due north from the initial point. In this area the line was known as the Fourth Principal Meridian. (Today there is a state historical marker at the initial point location.)

Townships and Ranges

The east-west lines that cross the principal meridian every six miles are known as the township lines. The north-south lines that intersect the baseline every six miles are known as range lines. The six-mile square block of land between the adjacent township lines and the two adjacent range lines is called a township.

Townships were identified by number north of the baseline; ranges east and west of the Fourth Principal Meridian. The descriptive information for our area townships was (and is):

Burke: Township 8 N. - Range 10 E. (T8N R10E);

Leeds: Township 10 N. - Range 10 E. (T10N R10E);

Vienna: Township 9 N. - Range 9 E. (T9N R9E);

Windsor: Township 9 N. - Range10 E. (T9N R10E).

Within a six-mile square township there were 36 one-mile square sections. These were numbered starting with number 1 in the northeastern corner of the township, then moving west with sections number 2 through 6, section 7 immediately south of section 6. The numbering then moved eastward with section 12 being immediately south of section 1. This back and forth pattern was repeated until reaching section 36 in the southeast corner of the township. (See the accompanying map of Windsor Township.)

Field Work

The surveyors literally walked across Wisconsin, south to north, west to east, measuring the land with a brass chain, sometimes called a Gunter’s Chain. The system of measurement used was based on the statute mile, subdivided into chains and links (not feet and inches). The chain was 66 feet long and consisted of 100 links, each 7.92 inches in length. There were 80 chains in a mile.

The fieldwork was done under the direction of a Deputy Surveyor. The survey team consisted of two “chainmen,” an ax-man, a surveyor, and a cook.

The chainmen carried the chain, one man at each end. One stood still holding the chain handle at one end as the other walked forward in a straight line to the full length of the chain. The first man then walked forward in a straight line past the second until the chain was fully extended again. This leap-frogging continued to the quarter section mark where the team “set a post” (or “raised a mound” of earth or stones). At 80 chains, which was the extent of the section, the surveyor set a corner post.

The ax-man cut brush along the way so that the chain could be held level and straight. The surveyor used a compass to make sure that the lines they were walking corresponded to straight lines along the meridians.

The original surveys were completed in two phases. The first were the outside lines of the townships, often called the “exterior lines.” The second phase addressed the “interior Iines” which subdivided the township into thirty-six sections. This typically involved a different crew of surveyors.

The surveyors wrote their observations in small leather field notebooks, which became the official record of the surveys. They were required to draw sketch maps and to provide section line notes. The notes included descriptions of the physical landscape, information on soil types, condition of the land, vegetation types, stream locations, lake and pond outlines, and evidence of human habitation such as trails and cabins.

Creation of the Official Plat Maps

Subsequently, the field notebooks were submitted to the Survey General’s Office where they were interpreted and translated into plat maps by cartographers. Two large hand-drawn maps were created for each township, one for the Surveyor General’s Office and one for the state. These maps and descriptions became the official documents, from which copies were created and made available to interested parties.

There were several land offices created in Wisconsin which opened and closed depending on the available land for sale. The maps and tract books created from the original surveys were essential for conveying information about what lands had been sold, were reserved, or were still available for purchase. Local land offices housed one set of the books; the General Land Office in Washington, DC, had another. As land was sold, the transactions were recorded at the local land offices and updates sent to Washington.

The Surveyor General’s Office made the original survey maps available to publishers, likely created as engravings or lithographs in the early years. The government didn’t handle the sale and distribution of maps to individuals and institutions. Most of the plat maps were and continue to be reproduced in books on a county-by-county basis. They are a convenient reference for local governments, private realty and surveying companies, historians, and the general public.

Important for travelers as well, the maps often included information about natural features (lakes and rivers) and man-made features (roads, towns, and villages). Most township maps included symbols for the locations of churches, schools, and cemeteries.

Online Access to the Original Notebooks and Field Notes

The original field notebooks, some now over 180 years old, are archived by the Board of Commissioners of Public Lands (BCLP) in Madison. The BCLP, in cooperation with the University of Wisconsin library system, now provides online access to images of the original notebooks and plat maps from the first land surveys. (See Online Sites below). This is fascinating information for anyone interested in the early history of the area.

Local Materials in the Society Library Archives

Our local society has an excellent collection of historic plat maps for Dane County. Among them are several large, hard-cover atlases for the years 1873, 1890, 1899, 1911, and 1931, some quite fragile because of their age. It is interesting to examine these vintage volumes, to compare and contrast the maps between the successive time periods and to admire the artistic representations.

Resources for Further Research:

Dane County Historical Society Newsletter, “Wisconsin Public Survey Records: Original Field Notes and Plat Maps,” Summer 2010.

Clark, Mary. Dane County Historical Society Newsletter, “Dane County Plat Maps,”
Summer 2011.

Bixby, Randy (BCPL Land Records Archivist). Presentation to the Dane County Historical Society, “Board of Commissioners of Public Lands,” September, 2010.

Online Sites: https://bcpl.wisconsin.gov/Pages/Home.aspx (Home page of the Board of Commissioners of Public Lands); http://digicoll.library.wisc.edu/SurveyNotes/Search.html (Online field survey records, hosted by the UW Digital Collections)

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