The sheer prevalence of maps in our daily lives, for journalism, entertainment, and personal convenience, suggests we are living in a golden age of cartography. But while the digital tools that enable the map’s increasing accessibility may indeed be new, the practice of mapmaking is nothing but ancient, and the creation of actionable cartographies stretches back centuries.
Beneath every map’s intended cartographic purpose lie veins of additional information, clue-laden contexts with the potential to inform contemporary research and historical inquiry. Leah Meisterlin and Gergely Baics, an urbanist and urban historian, respectively, are working together to unlock some of that latent data and interrelate them with a wide range of relevant datasets. Through this combination of emerging mapping technologies and deep historical research, the pair is opening up new seams in experimental urban research. Here, Meisterlin and Baics demonstrate their approach by remapping John Snow’s famous 1854 map of the London cholera outbreak and articulate the possibilities of this budding variety of urban archaeology.
The questions and patterns inferred through remapping John Snow’s cholera map are latent in other maps as well. Sufficient contextual information can instigate reinterpretation and reconsideration of that context as drawn. For example, we have been working with building footprint and land-use data encoded in the earlier described Perris atlas, digitized through a valiant, crowdsourced effort by the New York Public Library’s New York City Historical GIS Project.1 Some of the early research was presented last year at Raising the Bar (and has been written up for publication since then), and includes findings that have long interested urban historians but until now were impossible to study at the fine detail GIS mapping allows. Specifically, we have been examining land-use patterns in mid-19th-century Manhattan’s largely unregulated built environment, studying the separation, mixing, and varying intensity of commercial, industrial, and residential structures. Our reexamination of the Perris atlas through digital cartography opens ways to remap, at greater precision, key issues of urban development, land use geography, the Manhattan grid, social and economic clustering, population density, and residential crowding, to name a few. Notably, these maps can also provide context for introducing additional data from censuses, directories, or other sources to address a variety of urban historical topics. The opportunities for research are almost endless, ranging from the city’s economic and cultural landscapes to patterns of residential segregation or unequal access to public health and housing — issues that are always changing and ever-pressing.
- 1. The frontier in historical GIS is located precisely within such collaborative efforts as the NYPL’s Map Warper and Building Inspector sites and its more recent NYC Space/Time Directory. Designed to generate large amounts of historical GIS data, these will soon revolutionize the datascapes available to historians and the wider public to engage New York City’s historic landscapes. Read more in Urban Omnibus’ interview with Matt Knutzen, geospatial librarian at the New York Public Library.