Unmapped terrain and invisible communities: Analyzing topographic mapping disparities across settlements in the United States from 1885 to 2015

Mapping is an important and deeply political process. While much attention is now being devoted to the definition of boundaries (e.g., redlining, gerrymandering, redistricting), less is systematically known about where, when and at what scales maps are first created. This is an area of key concern because the creation of maps is key to generating spatial, topographic, demographic, or socio-economic data, resources which are of great strategic and economic importance. The absence of such information can, among other processes, impede strategic planning, political transparency, and sustainable development. There is thus much to learn about where and when maps are created, and which communities are either prioritized or “undermapped” within this decision-making process. We know that while Europe and North America are well mapped today, many of the world’s undermapped communities are located in the Global South. Similar disparities most certainly existed historically within Europe and North America too. To date, however, there has been very little quantitative examination of when communities within these regions were mapped, and what forces motivated these mapping decisions (e.g., economic expansion, resource extraction, sociocultural change). Herein, we use novel geospatial data sources to shed light on these processes by examining mapping in the United States between 1885 and 2015 from a quantitative, spatial-historical perspective. Specifically, we employ two data sources: Metadata on the United States Geological Survey (USGS) Historical Topographic Map Collection (HTMC, Allord et al. 2014), and historical settlement data from the Historical settlement data compilation for the U.S. (HISDAC-US, Leyk & Uhl 2018). HTMC metadata allows for identifying areas that were topographically mapped, and those that were not mapped, in a given point in time, and HISDAC-US allows for identifying areas containing human settlements, or built-up areas at that time. Based on these historical depictions of mapped and built-up areas, we use spatial and statistical analysis to measure the interactions between these two spatial processes