Although copper mining in New Spain did not enjoy the significance to the Mexican economy that it would in the early twentieth century, it did serve the larger interests of the Spanish colonial empire, primarily in the armaments industry and in the minting of coins. Besides describing the uses of copper, this concise book examines other facets of the Mexican colonial copper industry, centered largely in south-central Michoacán: government policy, mineownership, taxation, sources of supply and demand, labor systems, extractive and processing techniques, availability of capital, and patterns of internal and overseas trade. The analysis highlights royal efforts to improve the quantity and quality of production in the late eighteenth century. The book also includes a brief description of tin mining.

Copper was first produced by Indians who had mined it in preconquest times for making tools and ornaments; after the conquest, control soon shifted to Spaniards. At the beginning of the seventeenth century, the crown took over the largest mine and created an asiento (which lasted until 1787). For the next 150 years, lack of an adequate labor supply, inadequate credit sources, excise and other taxes, and high transportation costs all contributed to keeping production low and quality inferior—as long as the crown refused to raise the price it would pay for copper.

The situation changed in the late eighteenth century after Spain’s growing involvement in foreign wars increased the demand for copper. The crown created a monopoly on distribution to increase its reserves, but only after they ended the asiento in 1787 and set the price high enough to compensate the costs did production expand, actually doubling within a few years. Technical improvements introduced by mining engineers in the 1790s were not cost efficient and were abandoned. The estanco ended in 1809 after production exceeded royal demand. Barrett concludes that Bourbon efforts to improve the copper industry were ineffective; monopoly regulation was self-defeating.

With this book, which makes extensive use of Mexican treasury and mining tribunal records, Barrett begins to answer some of the questions colonial historians might well have asked earlier about the production of metals besides silver and gold. The monograph is strongest in its description of technical processes and attempts to reform them, and as an institutional study it provides valuable information on formal structures, legal regulations, and policy formulation in the copper industry. More work is still needed to produce a comprehensive picture of colonial copper mining. On the macro side, it would be useful to compare the relative percentages of copper produced and supplied to the crown by New Spain and Peru. Elaboration on production for local use and on marketing within Mexico would give a more balanced picture of the total trade pattern. Finally, given the preeminence of Michoacán in colonial Mexican copper production, a regional approach could more fully explain the interrelationship of economic and social factors in copper mining, in particular the nature of the labor force, the significance of mineownership for the distribution of prestige and power in the Pátzcuaro area, and the relationship of copper mining to other regional economic activities.