The tract books detail the original sale by the federal government of each piece of public land in the state, beginning with the opening of the Detroit Land Office in 1818. (These volumes do not include information about lands contained in private claims.)
The tract books for the Upper Peninsula are original records kept, beginning in 1847, by the land office in Sault Ste. Marie (in 1857 moved to Marquette). The tract books for the Lower Peninsula were copied, by hand in 1894, from an earlier record. After the earlier records were copied, some new entries were added and old entries were revised or updated. Some entries are dated as late as 1920. The tract books are arranged (in a somewhat random order) by township number, and within each township by section.
No names of townships appear in the collection, so it will be necessary for the researcher to discover the numerical designation in terms of township and range. A brief description of townships, ranges, and other details of the U.S. land survey system can be found (as of 2007) at the web site of the National Atlas of the United States http://nationalatlas.gov/articles/boundaries/a_plss.html. The range, township, and section of a particular place can be found using maps such as those in Henry F. Walling's Atlas of the State of Michigan (Detroit: R. M. and S. T. Tackabury, 1873, 1875, or 1884); or the Mapbook of Michigan Counties (Lansing: Two Peninsula Press, 1984). Range and township numbers for Washtenaw County Townships are as follows:
| Ann Arbor | R6E, T2S |
| Augusta | R7E, T4S |
| Bridgewater | R4E, T4S |
| Dexter | R4E, T1S |
| Freedom | R4E, T3S |
| Lima | R4E, T2S |
| Lodi | R5E, T3S |
| Lyndon | R3E, T1S |
| Manchester | R3E, T4S |
| Northfield | R6E, T1S |
| Pittsfield | R6E, T3S |
| Salem | R7E, T1S |
| Saline | R5E, T4S |
| Scio | R5E, T2S |
| Sharon | R3E, T3S |
| Superior | R7E, T2S |
| Sylvan | R3E, T2S |
| York | R6E, T4S |
| Webster | R5E, T1S |
| Ypsilanti | R7E, T3S |
|
Since the townships are arranged in a somewhat random order, an index to the 88 volumes by township and range has been created. It is found appended to this finding aid.
The information contained in an individual entry includes an exact description of the land purchased, the number of acres included in the transaction, the price per acre, the total purchase price, the name of the purchaser, the date of sale, the receipt number, and the person to whom the land was patented if this was different from the name of the purchaser. Quite often the date when the land was placed on sale appears on the page.
Indexes to the tract books by the name of the purchaser have been made. The most convenient (as of 2007) is the General Land Office Land Records web site maintained by the U.S. Bureau of Land Management: http://www.glorecords.blm.gov. Transcriptions of and indexes to tract books have been published for several counties. These can be found in the library's online catalog under the subject "Landowners Michigan ... County Indexes". Since these books were compiled from copies of tract books in other repositories, some names and locations may not correspond exactly to the library's copy. These indexes generally show the residence of each purchaser, a piece of information not included in the library's copy of the records.
A 1942 project by Anne Case and Theodore Clark produced a card file listing the purchaser's name and county for land purchases of 640 acres or more in these 19 counties: Antrim, Berrien, Cheboygan, Crawford, Gladwin, Ingham, Ionia, Iosco, Isabella, Lenawee, Newaygo, St. Clair, and Wexford in the Lower Peninsula, and Gogebic, Keweenaw, Luce, Marquette, Menominee, and Schoolcraft in the Upper Peninsula. The card file is not part of this electronic finding aid and is only available at the Bentley Library.
