Mapping Space : An Analytical Tool for Environmental History

What is the relationship between the spaces we live in and the stories we tell?

In 2011, the tech magazine Fast Company published a short article about the Stanford Spatial History Project. The article focused on the historian Richard White's project of mapping late nineteenth century railroad freight tables in order to better understand how the transcontinental railroad shaped space in the western United States. The Fast Company author explained that the visualization methods employed by White and his team "open up new ways of telling history" because they enable researchers to ask new questions of historical data.

"A River in Time" draws on some of the same concepts and digital methods (including ArcGIS) to map the Neponset River through space and time. Although our spatial range -- from the Blue Hills Reservation in Canton, MA to the Boston Harbor Islands -- is relatively small, the temporal range of the project is broadly conceived. Our goal is to better understand the ways that human and environmental interactions in this region have shaped each other from the area's prehuman history to the present.

Figure 1. "A River in Time" Overview Map | Made with ESRI ArcGIS software.

The map above contains an overview of each of the places on the Neponset under consideration in this project. Because this map was created using ArcGIS software, each point is georeferenced using latitude and longitude (or the latitude and longitude of a place that approximates the general area under discussion). ArcGIS can store additional data that accompanies the spatial coordinates provided by the researcher. Thus, if you click on any single point on the map, you will see information such as the site address, the human use of the site ("category"), and the temporal period in which the site enters our environmental history of the Neponset.

Click the double arrows on the lefthand side of the map to expand the legend and you will see each site categorized by its most prominent human use through time. Providing this legend raised a number of intellectual issues for the creator of this map, as a decision had to be made about whether to provide a reference that characterized each site by use or by the temporal period in which they enter our story of the Neponset.

Once the decision was made to categorize these sites by use (i.e. subsistence, commercial, transportation), the map creator had to grapple with the fact that any categorization poses problems and has the potential to introduce artifacts into the results of a historical analysis. To put it simply, names, concepts, and categories impact the way we tell histories. This is no less true of environmental history. Humans engaged with many of these environments in a multiplicity of ways throughout time and, to characterize the Indigenous Massachusett people as engaging only in "subsistence" activities, while the early English settlers most frequently engage in "commerce," for example, raises questions about the lens through which we are viewing these different societies.


Why Map?

However, if we understand these categorical uses of the environment not in terms of cultural characteristics, but as functional approaches to the environment that can be shared across human groups and through time, imposing these sorts of categories onto the places in our maps can help us to ask new questions of our historical data. Questions such as: where do different human activities cluster on a map? In certain environments? In certain temporal periods? How do they separate out along the axes of space and time? In this way, you can use the legends in the lefthand corner of this map (and the maps that follow) to begin to analyze the different ways that humans engaged with the Neponset river and surrounding environments through time.

The map has layer filters divided into four temporal periods, each layer featuring a few sites that are central to the environmental history of the Neponset river in that time period. After turning a temporal layer on, click on the arrow to the right to turn on the category legend. This will tell you the category of use for each site.

As you select the layers in the map below, think about how visualizing the spatial spread of these places can help us begin to trace historical trends in human-environment interactions. The map is accompanied by short commentary to prompt this type of analysis.

Four Temporal Periods

c7,500 BP - 1629 | 1630-1800 | 1801-1929 | 1930-2022

Figure 2. "A River in Time" Map with Four Temporal Layers | Made with ESRI ArcGIS software.

By turning the temporal layers (and the associated legends) of the above map on and off, you can start to analyze historical change over time.

  • For example, in the first layer, which covers the ridiculously long period from 7,500BP (an archaeological designation) to 1629, the legend tells us that the environment was mostly used for subsistence, with some commerce, in this period. This wide-ranging land-use makes sense with what we known about subsistence land use patterns -- that is, they require large territorial ranges with a broad range of environments.
  • By turning on the 1630-1800 layer, we see the concentration of commercial uses clustering around the river at what became Dorchester and Milton Lower Mills. This tells us something not only about the way that societal uses for the Neponset changed, but also something more broad about how different ways of engaging environments use space in different ways (i.e. diffuse spatial patterns for subsistence and concentrated for the "intensified landscapes" of commerce)
  • When we turn on the 1800-1929 layer, we see that land-based transportation methods become more common, but they seem to follow in the path of the river. We might conclude from this that even the patterns created by fossil-fuel drive land transportation infrastructure are shaped by waterways. But should we? This temporal layer raises an interesting discussion about historical causation and research methods. Looking at the map alone, we might draw the above conclusion. However, the historical research that went into our narrative StoryMap on the next page revealed that two of the proprietors of an important paper mill on the Upper Neponset (Tileston and Hollingsworth), were also members of the Dorchester and Milton Railroad Branch Company that built the railway through this area in the late nineteenth century. So maybe the historical patterns of transportation are created by individual agency and economic ambition? But commerce, as we will see, is most definitely shaped by the flow of the Neponset's waters. Industry relied upon the shape of the river and the built environment created by dams to power production. The point is that mapping space AND using traditional history research methods help us to write more complex and interesting environmental histories.
  • Finally, when we turn on the layer that takes us from the 1930s to the present, we are able to see how many of the sites that are currently designated as "recreational" are layered on top of past industrial sites. This visualization highlights the importance of the local community and the EPA's current efforts to decontaminate the river, especially in spots where the public congregate to enjoy the Neponset.

Natural and built environments change over time (and how historical maps *sometimes* help us see it)

Figure 3. "A River in Time" Map with Georeferenced Historical Map Layers | Made with ESRI ArcGIS software and MapWarper.

The above map includes "georeferenced" historical maps layered onto an ArcGIS "basemap." The point of this map is to try and visualize the ways that historical environments have changed over time.

  • BUT historical maps are not always very accurate with respect to the spatial coordinates we use in modern maps, so georeferencing these maps cannot always give us a perfect picture.
  • When things do work out though, we are able to see, as in the above 1876 map produced by the Massachusetts State Board of Health, the way that the river and surrounding regions have changed (or not) over time. In this case, our late nineteenth century Neponset looks pretty similar to the shape of the present day Neponset at Milton Lower Mills. What might this tell us about the timing of the formative industrial period?
  • The 1876 map of the Neponset was created by the MA State Board of Health in the context of nineteenth century malarial outbreaks and a push to drain marshlands that accompany river shorelines.1 Georeferencing historical maps like this one might prove useful to recent environmental history projects that seek to understand the connection between the hydrology of New England rivers and public health outbreaks from the seventeenth through nineteenth centuries.2

Notes

  1. Peter Boucher, a former graduate student of Dr. Valencius, conducted research on historical environmental change in the Neponset's marshlands and makes this connection between the publication date of the MA Board of Health map and nineteenth century malaria concerns.
  2. Strother E. Roberts, "Hydrology and the History of Malaria in Seventeenth-Through-Nineteenth-Century New England," 2013.