Informazioni sulla fonte Stati Uniti, Archivio delle prime proprietà terriere e mappe catastali delle borgate, 1785-1898 [database online]. Lehi, UT, USA: Operations, Inc., 2011.
Dati originali:

Public Land Survey Township Plats, compiled 1789–1946, documenting the period 1785–1946. Microfilm publication T1234, 67 rolls. NAID: 566647; Records of the Bureau of Land Management, 1685–2006, Record Group 49. The National Archives in Washington, DC.

 Stati Uniti, Archivio delle prime proprietà terriere e mappe catastali delle borgate, 1785-1898

La creazione delle mappe catastali delle borgate iniziò con l'indagine sulle terre pubbliche (Public Lands Survey) degli Stati Uniti che iniziò con il Land Ordinance Act del 1785. Questa raccolta include le mappe complete o parziali di Alabama, Illinois, Indiana, Iowa, Kansas, Mississippi, Missouri, Ohio, Oklahoma, Oregon, Washington e Wisconsin. Le mappe furono preparate in base alle note delle indagini sul campo prese dagli addetti alla rilevazione e includono dettagli fisici e miglioramenti manuali. Indicano le linee di demarcazione delle borgate e delle sezioni, i numeri delle sezioni, gli acri dei poderi e talvolta i nomi dei proprietari terrieri.

The township plat maps in this database began with the Public Lands Survey in the United States initiated by the Land Ordinance Act of 1785. In order to sell or otherwise dispose of land in the public domain, the government first had to have the lands surveyed. The Public Lands Survey divided public lands west of the original colonies into a grid of townships and sections. A township was a square six miles to a side and contained 36 one-square-mile (or 640 acre) sections. These maps became the basis for property claims as public domain lands were transferred to private ownership.

This collection includes maps of townships in all or parts of Alabama, Illinois, Indiana, Iowa, Kansas, Mississippi, Missouri, Ohio, Oklahoma, Oregon, Washington, and Wisconsin. A typical plat map will cover one township, and the usual scale is two inches = one mile, though this collection also includes maps that show partial townships or sections within a township or maps created from multiple surveys or resurveys, so there can be multiple plats associated with a single township. Also, these maps were originally produced in triplicate, and for some states both the local office copy and the copy that was sent to the Government Land Office in Washington, D.C. (the “headquarters” copy) are included.

Township plat maps were prepared from the survey field notes taken by deputy surveyors and can include details such as roads or trails, lakes and rivers, forest or swampland, Indian lands, and improvements made on lands that had been settled before the survey took place. They also indicate township and section lines, section numbers, and acreage of holdings.

Information on a map can vary depending on when the survey was done and whether the lands were populated yet. Names of settlers, patentees, and claimants appear on lands where some settlement had taken place before the survey, and plats containing names of landowners in this collection have been indexed. Some maps also record land patent dates.

Meridians, Townships, and Ranges

At the top of a map you will typically find a description of the plat given in terms of township and range. This may be abbreviated with letters and Roman numerals, for example: T.II.N.R.I. East. In this instance, the T stands for township, the R stands for range, and the N for north. It means that this piece of land is two townships north of the base line and one range east of the meridian. This is explained further below:

“A meridian is an imaginary line running directly north and south, from pole to pole. East and west measurements within the meridian are then counted form this line… To help complete this meridian grid, there is a horizontal line that runs east and west, intersecting the meridian line at a right angle. This horizontal line is identified as the base line. It is the line from which north and south descriptions begin their measurements….

“The term township refers to a six-mile-square piece of land within the meridian. Ranges are imaginary lines running north-south, set six miles apart—the width of a township. When measuring land within the meridian, the township, or tier, directive of the land description always indicates a count in a north-south direction from the base line. The range directive, in turn, indicates an east-west count of townships within that same meridian. A description of T3N R2W, for example, would count three townships to the north of the base line and two ranges (township widths) to the west of the meridian.” (From Hone, Wade E. Land and Property Research in the United States [Provo, UT: Ancestry, 1997], p. 103.)