Working with Historic Maps

One of the most important strengths of historical archaeology is our ability and willingness to combine anthropology, dirt, and the historical record.  Using documents to aid archaeological research is one of the defining characteristics of the discipline.  These come in many forms–including, but certainly not limited to, deeds, journals, diaries, letters, probate inventories, wills, church records, census records, tax assessments, photographs, paintings, and maps.  Before each dig, we compile  documents and sources which may inform our excavations and interpretations.  The beginning of most archaeological site reports includes a discussion of the context in which we think our site falls and the documents used to provide that information.

We spend a great deal of time thinking about these sources of information and how they relate to what we encounter in the ground.  In an ideal world, what we find in the historical record is helpful and informative and matches what we find in the archaeological record. In practice, the historical record is more often than not full of gaps, contradictions, information not relevant to our site, or information that suggests the feature we encountered shouldn’t exist.  Maps are both among the most helpful and most confusing sources of historical evidence with which we work.  Questions of spatial accuracy aside, the shapes of historic features on maps can be as enigmatic as they are simple.

Sanborn 1891

Sanborn Fire Insurance Map, 1891

Sanborn 1897

Sanborn Fire Insurance Map, 1897

This summer, as in years past, we have turned to historic maps in an attempt to better understand the archaeological record.  At the Schwar’s sites, we have been able to identify a narrow date range for the construction of the present structure by tracing the history of the property and its buildings as they are depicted  on a sequence of historic maps.  While the neighborhood was developed relatively early in Annapolis’ history, the current structure dates to around the turn of the 20th century.  Our research with these maps has revealed the building that stood on the site until the end of the 19th century, when it was replaced with the current one.

Overlay of Sanborn Maps

Overlay of Sanborn Maps

Using the same technique for incorporating geospatial coordinated and overlaying multiple spatial datasets or maps as described previously on this blog (see: Why are we digging where we are at Wye?), we were able to superimpose both the current building with the earlier one.  This gives us an idea of where we can expect to find evidence of this previous building in the ground.

This week, in Unit 25, as we were cleaning the top of a level we believe to be sterile subsoil, we found several features cutting into that layer.  Their position in relation to the current yard don’t make sense as a fencepost.  It is possible these are the remains of posts, either from a fence or a wood frame building.  Could these features be related to the earlier building?

TU 25

Test Unit 25

Looking on a map at these buildings and the ones we will continue to excavate at Wye House in a few weeks,  one can’t help but feel they are looking at an intellectual treasure map, one that if followed, will help us answer the questions we have of people in the past.  These shapes on paper are evocative of buildings we know once existed and hope still exist (at least partially) in the ground.  As we excavate, we constantly compare what we find archaeologically with the enigmatic shapes found on our maps.  Even though they’re little more than labeled rectangles, these shapes give us one of our best glimpses into a vanished landscape.

1 Comment
  1. Historical maps are very important in terms of identifying what history transpired in a place and time. A project I worked on required us to look at a group of historical buildings on an old cartograph and decide which building was the leather tannery based on its necessity for running water from a stream or river.

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