The Geography of Grain Trade in New Spain, 1730–1820

Over the last twenty years historians have unveiled a world of everyday commercial  relations that ran deep and reached across vast areas in New Spain. They included networks  of merchants, sophisticated logistics of the muleteer business, and blurry boundaries  between the subsistence and commercial sectors. Yet, when the gaze turns to grain  trade, historical discourse switches to images of precarious markets isolated from one  another by the tyranny of distance. The choice of terminology (e.g. hinterland) and graphic  representations (rings, maps centered on one city's supply) strengthens the perception that  grain supply areas were univocally related to one consumer area, rather than being part of  an integrated or competitive environment. In this paper I challenge this traditional view of  fragmented grain markets by constructing an alternative cartographic representation of  grain transactions between producing cereal areas and multiple consuming centers (cities  and mines) in central Mexico from 1730 to 1810.  I use a Geographic Information System to integrate diverse published and new archival  evidence from city granaries and private transactions. The result is two maps, one for maize  and one for wheat, that provide a snapshot of grain trade in the late colonial period. They  show that grain trade took place at a regional scale, typically involving journeys of several  days. Moreover, the geographic patterns between origin and destinations resemble a lattice  instead of a ring or concentric configuration expected in the traditional characterization of  grain markets.  In sum, grain supply areas in New Spain transcended the local sphere and overlapped  with each other, resulting in a more competitive economic geography. These characteristics  influenced food supply policies and access to food in the viceroyalty in the late colonial  period in ways that historians still need to understand better.