Two of the most productive approaches to historical investigation deal with population and region. Since 1964, for instance, the Cambridge group has produced reconstructions of social behavior and economic change in preindustrial England. In studies more properly Mexican, an emphasis upon region has yielded a controlling focus, which, in Eric Van Young’s words, enables the historian to “minimize the unique or eccentric, while still allowing meaningful generalizations.” It is a measure of the merit of Michael M. Swann’s work that it combines the power and rigor of both avenues of inquiry.

Swann’s work is one of several carried out under the Joint Oxford-Syracuse Population Project. It focuses upon Nueva Vizcaya, the region including the uplands of Chihuahua and Durango, the Bolsón de Mapimí, and the towns and the missions linked by the upper Rio Grande in the province of Nuevo México. Swann argues that Nueva Vizcaya, with some 140,000 inhabitants circa 1740, is the proper object of a detailed study that would “link the evolution of its settlement network with a growing population and a changing social structure” (p. xxvii). To this end, Swann details the genesis of the region, describes its overall secular growth, analyzes population change (1765-1810), and provides insight into the ecology of frontier Durango. The quantity and quality of his research are truly staggering; the adjective “thorough” does Swann little justice.

Social historians will find much to ponder in this work. Swann concludes that a pronounced decline in the rate of endogamy and in the significance of propinquity in choosing a marriage partner “reflected a loosening of social restrictions” (p. 259). His analysis of ethnicity and status makes a substantial contribution to the debate by documenting “a deterioration in the importance of race as a determinant of social position” (p. 369). Swann’s analysis of family size is instructive. His effort to correlate its measure with ethnicity and wealth suggests its possibilities as a proxy for unobserved variables. The ecological analysis of urban Durango is striking. Swann links his work to larger issues, such as the utility of the model of the pre-industrial city, or “the usefulness of a definition of class based on wealth” (p. 396).

To be sure, this is not a study without blemish. Its prose is dense; sentences of eighty words are not unusual. The lengthy methodological and bibliographical discussions in each chapter are useful, but detract from the line of argument and belong in an appendix. Superfluous figures and tables abound. More seriously, Swann regards increasing mining output as an axiomatic explanation for population change in Nueva Vizcaya between 1790 and roughly 1805. But the mining boom was limited to the early 1790s; and the boom in Sombrerete, for instance, to 1792 through 1795. Still, this is a major contribution to the historiography of colonial Mexico. Swann has made tierra adentro terra incógnita no more.