The historian Patrick Spero, writing in the Pennsylvania Magazine of History and Biography, notes that the word “‘war’ might strike some today as an exaggeration,” but that the “causes underlying this conflict and the actions taken by both parties were similar to those seen” in other wars. Spero notes that both “Maryland and Pennsylvania mustered militias, built fortifications, and took prisoners” and that “most significantly, many of those involved in the fighting called it a war,” for this was a “conflict between two competing governments, each of which sought absolute… control over a disputed area.”
King George II and the Chancery Court intervened in 1738, temporarily setting the border at 15 miles south of the most southern residence in Philadelphia, until a more exact boundary could be set. A prisoner exchange was initiated. Skirmishes flared until 1767, when two neutral English astronomers, Charles Mason and Jeremiah Dixon, finished their four-year-long survey.
Spero notes that old belligerence is hard to forget, as even “[l]ater in the nineteenth century, [during] a time of pronounced state identity and allegiance, the war caused feuds between contending historians from Pennsylvania and Maryland.” Mason and Dixon’s survey charted the boundaries between two aristocratic families, but ultimately their task had far more cultural significance, an exercise in what the philosopher Henri Lefebvre calls “the production of space.”
The legal anthropologist Rosemary J. Coombe, writing in the Stanford Law Review, argues that space is not a “container but a medium through which identities are created. Maps, to the extent that they reify and objectify spaces, also legitimate particular subjectivities.” The Mason-Dixon line, based not on the course of a river or the shore of a lake, is an example of how an imaginary line on a map can “legitimate particular subjectivities.” Originally conceived as a means of differentiating that which belonged to Calvert and Penn, the line would come to symbolize the division between North and South, free-state and slave-state, separating America from itself.
As the historian Charles Desmond Dutrizac explains in The Pennsylvania Magazine of History and Biography: “In the eighteenth century, most English colonists on the North American mainland were uncertain about the physical limits of provincial jurisdiction.” But that borders exist is perhaps the one inviolate creed of the international political order. By contrast, it’s surprising how, during earlier periods, ambiguity was sometimes tolerated–until it wasn’t.