GIS stands for Geographical Information Systems. The growing field of digital history cannot deny the impact of new technologies. As part of old technologies becoming new, there is something called Historical GIS. GIS is a spatial database that integrates map-based information on the historical location of certain entities [1]. Entities can exist in the form of industrial farms, rivers, and census districts. This information is then layered with quantitative or qualitative data. Examples of qualitative and quantitative metrics include population, production, and pollution levels [1].

Teaching the Salem witch trials with Historical GIS offers a new perspective to reconstruct the past and provide clarity. The Salem witch trials are a historical controversy, and scholars have used Historical GIS in retelling the events. The Boyer and Nissenbaum map of accusers and accused has been used and layered with village tax data. This visual insight allows us to extract new information and establish deeper meanings. They were able to see that wealth was distributed fairly homogeneously throughout the community [2].

Another example is the remapping of accusers, accused witches, and their defenders, incorporating new ideas from recent studies. Mapping and remapping data to spatialize it allows for patterns to become visible that were not apparent without spatial visualization. In the case of Salem GIS, this helps to reestablish the importance of social factors operating within the witchcraft accusations. Data can be simultaneously layered with other parameters to reveal more [2]. For instance, mapping social status and wealth data provides a better snapshot of the witch trials [2].

The insights provided by Historical GIS evolve the subject of the Salem witch trials. Although the trials have been studied previously, this approach refines and evolves the subject by exposing information not visible to the naked eye. The sequencing of maps showing the explosion of accusations slightly reminded me of epidemiologists tracking the spread of a disease. The geographical scientification that takes place in mapping qualitative data is quite sophisticated, in my opinion.

Visual overlays require the query or measurement of spatial relationships between features. To do this, they are lifted off historical maps and converted into vector GIS layers [3]. I think this is really cool because the last time I read anything about a vector was in my matrix linear algebra class. Vectorizing the feature of interest entails digitizing points, lines, and areas. Although time-consuming, this method adds a wealth of data, allowing for more workability in the long run [3]. However, the practicality and accessibility of this to teachers, researchers, and scholars depend on access to high-quality scanners, prepared digital images, or digitizing tablets [4].

Exploration of geographical patterns that account for temporal and spatial scales allows new questions to be developed and visuals that create new interpretive arguments [5]. Linking social, spatial, genealogical, and legal relationships can bring a whole new life—a literal virtual reality.

Footnotes

1. Knowles, Introduction, 452.

2. Knowles, Past Time, Past Place: GIS for History, 25.

3. Knowles, Past Time, Past Place: GIS for History, 8.

4. Knowles, Past Time, Past Place: GIS for History, 16.

5. Knowles, Past Time, Past Place: GIS for History, 32.

Bibliography

Knowles, Anne Kelly. “Introduction.” Social Science History 24, no. 3 (2000): 451-.

Knowles, Anne Kelly. Past Time, Past Place : GIS for History. Redlands, Calif: ESRI Press, 2002.