… the best and surest pathway to the good life runs through the city.

-Allen J. Scott

Professor of Geography and Public Policy at UCLA, Allen J. Scott’s words of support for one of mankind’s oldest inventions come in a review of Harvard Professor of Economics Edward Glaeser’s book Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happieran aptly-named 300+ page argument that much of humanity’s collective progress owes credit to the so-called concrete jungle. While I’ll admit I’ve not had the chance to read Glaeser’s entire work, it’s been on my reading list for quite some time now, recently rising to the top after I stumbled across an old podcast episode featuring Glaeser as a guest.


Edward Glaeser, author of Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier.


While I’d love to spend a few hundred words raving about Stephen Dubner’s Tell Me Something I Don’t Know and Freakonomics Radio podcasts, the purpose of this blog is to investigate the role played by the institution of slavery in America’s development, not for me to go off on tangents. As such, I’ll cut to the chase—Glaeser’s major premise inspired me to investigate the following question: How did the institution of slavery interact with the development of the city in 19th-century America? In other words, how did slavery’s role shape the growth of cities, and how did the growth of cities shape the role of slavery in 19th-century America? Additionally, what characteristics of slavery and features of cities may explain such a relationship?

Armed with data from the NHGIS and a new toolbox of mapping skills following this week’s HST 251 tutorials in Flourish, I set out to seek answers. After a few hours of chopping, mixing, and baking CSV and GeoJSON files, I was able to cook up the following visualizations in an attempt to answer my question from a geospatial point-of-view: time-series progressions of US population by percentage-enslaved and urban inhabitants.




While I’ll start with a reminder that these maps don’t tell the whole story, they tell an interesting one: upon side-by-side comparison, the visualizations reveal a stunning stagnation in urban center growth south of the Mason-Dixon Line, precisely where slavery persisted until Lincoln’s 1863 Emancipation Proclamation. Such uneven growth is best seen in the 1840-1850 frames of the Urban Inhabitants visualization, where counties across the newly-established Northwest Territory blossom in emerald with urban development while counties in the Antebellum South remain a bland shade of grey-green. In particular, one may observe that the majority of urban center growth in the South is concentrated in the pre-existing urban areas of Charleston, SC, New Orleans, LA, and colonial establishments of lowland Virginia and North Carolina, evident of the cotton capitalism that shaped southwestern growth to spread wide and thin onto plantations, prey of the city. This contrasts the boom of manufacturing and skilled trade which drove northwestern growth, evident in the establishment of town-centers along rivers and lakes in the mid-19th century.

Realizing such correlation between a lack of slavery and urban growth, unfortunately, does not answer the question of causation: was urban growth in the south stunted due to the institution of slavery, or was slavery perpetuated in the south in part by a stagnation in urban growth? On one hand, Schermerhorn’s Unrequited Toil notes that the easy profits guaranteed by cotton capitalism may have restrained innovation and growth of technical commerce (which drove urban growth) in the South, while such innovation flourished in the North out of competitive necessity; on the same hand, the very nature of cotton capitalism made geographic sparsity a necessity, as economies of scale dictated that larger plantations made larger profits. On the other hand, one could argue that a lack of urban centers is to blame for the perpetuation of slavery, as cities enabled radical ideas and plans of revolution to spread by word of mouth, publication, and assembly. Gabriel Prosser’s Rebellion, Denmark Vessey’s Rebellion, and many of the African Methodist Episcopal Church’s organized protests rose from the pure proximity of visionaries and the dynamics of close-quarter communication, bonding, and trust; thus, it’s impossible to say unilaterally that the chicken came before the egg, or that the egg came before the chicken.

Gabriel Prosser, planner of a suppressed 1800 slave uprising.
Denmark Vesey, planner of a suppressed 1822 slave uprising.

Instead, I’ll leave the question of causation with you, the aspiring historian. I didn’t make this week’s visualizations to argue for one side or the other; rather, I followed the advice of Stanford Professor of History Richard White, keeping an open mind. After all,

… visualization and spatial history are not about producing illustrations or maps to communicate things that you have discovered by other means. It is a means of doing research; it generates questions that might otherwise go unasked, it reveals historical relations that might otherwise go unnoticed, and it undermines, or substantiates, stories upon which we build our own versions of the past.

-Richard White