The obrajes of the Sierra and the plantations of the Coast are the poles around which, in different eras, the economy of the Audiencia of Quito seems to revolve. Woolen cloth and cacao are the two products that allowed this territory to participate in regional and international commercial circuits, and have attracted the most attention from historians in the last two decades.

In a region lacking large mining centers, encomenderos were from early times compelled to develop activities that would allow them to move in the Andean colonial sphere, which was dominated by the “Rich Hill” of Potosí, the actual force behind the formation of this great interregional market, as Carlos Sempat Assadourian has demonstrated. The inter-Andean corridor and its plateaus, suitable for the raising of sheep and a source of ready Indian labor, facilitated the development of the obrajes that were set up in Indian communities, on private haciendas, and in urban areas.

Scholars have debated the effects of the Guatemalan Revolution (1944-1954), i.e. the political and social changes carried out during the decade, on the closed corporate community. Many scholars, including the anthropologists Carol Smith and Ralph Beals, have looked at the political pressures and changes during the Revolution in attempts to explain the decline of the traditional community during the decade. Meanwhile, the historian Jim Handy has challenged the common political explanations for the downfall of the community and questioned the degree to which the communities are “closed” and “corporate.” Most scholars agree, however, that the revolutionary period witnessed a breakdown in the traditional village structures.

By comparison with the rest of Latin America, Mexico's post-revolutionary political stability has long fascinated historians and social scientists. One explanation for relative political peace is the comprehensive land and labor reforms President Lázaro Cárdenas implemented in the 1930s. These created a base of social support for post-revolutionary elites. In contrast, the absence of significant land reforms and the failure to devise hegemonic labor regimes in South America resulted in class stalemates, forcing elites to fall back on the militarized state. Land and labor explain the difference between Mexican stability and South American instability since 1920.

Unique sources of historical, demographic, toponymic, and linguistic information, the mission registers (baptisms, matrimonial inquiries, marriages, burials, and census) of Baja California have been used in varying degrees to good effect by Carl Sauer, Peveril Meigs, Sherburne Cook, Homer Aschmann, and Pablo L. Martínez, among others. What is, alas, not so unique, but true of many parochial archives in Mexico, is the fact that until quite recently they were often left exposed to the elements, rodents, insects, and looters. Gerhard attempted to make an inventory of the known surviving registers in 1952-1953, when he found some of them totally unguarded and uncared-for. This work was followed by Woodrow Borah in the 1970s, and since 1971 Mathes has brought this calendar upto-date, and has obtained or personally produced microfilm of the entire corpus, including certain folios which have since disappeared. Here we shall summarize the tortuous history of the dispersal of these documents.