Chronology of the Williams Farmstead Artifact Assemblage

Historical evidence indicates that the Williams family lived on their farm from ca. 1871 to 1905, and the recovered artifacts are indeed representative of this time frame. But the process of interpreting the chronology of artifacts from a historic site is not as easy as one might imagine. Identifying the timeframe of an occupation based on a large artifact assemblage involves understanding the full life cycle of individual artifacts.

After an object is manufactured, it is purchased or obtained by a consumer. The object may be used for a short period of time, or a long period of time, and it may be modified and recycled for some use other than its intended function. Ultimately, each object gets broken and discarded, lost, or left behind so that it then enters the archeological record. For historical archeologists, some items are good chronological indicators because they represent a distinctive type or have distinctive markings that can be dated. But in any given assemblage, most of the items recovered are not particularly informative for chronological assessment. Broken bottle glass, plain whiteware sherds, and rusted iron pieces are the most common items found, and they are obviously of historic age. Unfortunately, they cannot provide much additional chronological information, and archeologists must focus their efforts on items that are temporally sensitive.

For the Williams farmstead material remains, the chronology must be assessed based on the items that have diagnostic markings (such as maker’s marks, company or product names, or patent dates) or represent a class of objects specific to a particular time period, such as cut or wire nails. Both types of evidence are useful for evaluating the age of the farmstead material culture.

For any historic site, we cannot assume that the manufacture dates for any particular item represent the time when that item was acquired, used, or discarded. The main problems with making this assumption are: (1) Items with known beginning manufacturing dates could have been made and purchased many years or even decades after their initial appearance; (2) Items with known ending manufacture dates could have been made for many years before they stopped being made; (3) Items with known beginning and ending manufacture dates could have remained unsold in a wholesale or retail store for many years or even decades; and (4) Items can be resold or traded from one consumer to another years or decades after they were made.

Archeologists call this phenomenon the “time lag” effect, and it must be considered when studying artifacts from any historic sites. Historic archeologist William Hampton Adams defined time lag as “the difference between the date of manufacture and the date of deposition,” noting that “the manufacturing date for an artifact cannot be equated with an artifact’s use date.” Adams summarized this concept succinctly when he said: “…it takes time for these objects to be broken and discarded.”

For nineteenth-century historic sites, some time lag between manufacture and deposition should be expected for almost all artifact categories, but the degree of time lag will vary by artifact types. A site occupied only for one year in 1895, for example, would probably have relatively few items made in the 1890s but many items made in the 1880s and 1870s. The average time lag for many fragile items (glass containers and ceramic dishes) might be a few years, while the lifespan of many durable items (hand tools) was much longer. Historic sites may even yield heirloom items—treasured possessions that were handed down from one generation to the next—and such objects were often manufactured many decades before they were got broken and discarded or lost.

"... it takes time for these objects to be broken and discarded."

–William Hampton Adams, 2003

Graph showing chronology of 128 temporally diagnostic artifacts
Chronology of 128 temporally diagnostic artifacts with known beginning dates of manufacture. Enlarge to learn more.
Graph showing chronological distribution of 26 temporally diagnostic artifacts
Chronological distribution of 26 temporally diagnostic artifacts with known beginning and ending dates of manufacture. Enlarge to learn more.
Graph showing chronology of cut nails and wire nails from the farmstead
Chronology of cut nails and wire nails from the farmstead. Enlarge to learn more.