In 1848, Mexican diplomats signed the Treaty of Guadalupe Hidalgo, surrendering over 500,000 square miles of land to the United States. Unbeknownst to either side at the time, an immeasurable fortune in gold, silver, and copper also passed to the northern invaders. Within months, veterans of the U.S.-Mexican War discovered gold in California. This transformative event inspired speculative prospecting on both sides of the newly established border, leading to bonanza silver strikes west of the Rocky Mountains and copper discoveries farther to the south. In Mining the Borderlands: Industry, Capital, and the Emergence of Engineers in the Southwest Territories, 1855–1910, Sarah E. M. Grossman explores the role that mining engineers played in the growth and development of the industry in the remote territories of Arizona and New Mexico, along with their neighboring Mexican states of Sonora and Chihuahua. According to Grossman, mining engineers proved not only innovators and pioneers in their field, but also a vital linchpin between eastern investors and southwestern mining operations, radically changing the industry in the Southwest.

Drawing from memoirs, personal papers, and corporate archives, Grossman skillfully documents the evolving technological and managerial trends across the decades of her study. During the 1850s, prohibitive taxes on foreigners and racial violence drove Mexican gold miners from their former patrimonial lands in California into the forbidding deserts surrounding the international boundary line. As they discovered silver and copper, American entrepreneurs took notice and sent their own agents to establish mines in the harsh environment. Autodidacts who learned the profession through on-the-job training and experience filled the ranks of the first generation of mine managers. Among them, however, was a small cadre of privileged, European-educated engineers, who found themselves improvising and experimenting with the limited resources and primitive infrastructure of the region. Often living in areas that were both culturally and environmentally foreign, these credentialed professionals undertook a variety of responsibilities including conducting surveys, performing ore assessments, drafting operating plans, and occasionally managing entire sites.

Faced with expensive mine failures, eastern investors favored those managers with a formal education and promoted the establishment of engineering and mining schools in the United States. The emergent Columbia School of Mines, Massachusetts Institute of Technology, and various state and territorial colleges trained the postbellum cohort of mining engineers. This generation of technocrats confronted new ethical dilemmas as they navigated the divide between the speculative realities of southwestern mining and the needs of eastern shareholders, blurring former lines between disinterested scientists and optimistic investors.

The expansion of the telegraph and household electricity during the 1870s and ’80s fueled a growing market in copper wire. This corresponded with the ascension of Yankee-friendly Mexican dictator Porfirio Díaz, which further facilitated the growth of U.S. copper-mining interests on both sides of the border. To meet growing demands, engineers developed new techniques of “mass mining” to refine low-grade ore. Such operations required tremendous capital, which forced a restructuring and consolidation of mining companies. Turn-of-the-century mining emphasized technology over the once-valued skilled labor of individual miners. In this environment, mining engineers encountered fewer freedoms and less autonomy than their forebears, as they disappeared into the corporate bureaucracies that their successes helped create.

As an industry case study of the U.S.-Mexico borderlands in the decades following the American conquest of the region, Grossman's work is a welcome addition to the historiography. Mining the Borderlands is a useful complement to David Igler's Industrial Cowboys: Miller & Lux and the Transformation of the Far West, 1850–1920 (2001). Both authors explore the evolution and corporatization of quintessential southwestern avocations. Indeed, Igler's cowboys and Grossman's miners ultimately emerge as wage-earning corporate cogs rather than the solitary entrepreneurs of American myth. This reality is vital to understanding the true nature of western industries in the second half of the nineteenth century.

One small quibble with the book is its geographic scope. Grossman confined her study to the “various mining districts surrounding the U.S.-Mexico border in and below Arizona and New Mexico” (p. 9). This excluded, from anything but passing mention, the American Smelting and Refining Company (ASARCO), whose El Paso operation grew to be a major economic, social, and environmental influence on the region. Although located just outside of the New Mexico territorial boundary, the triangular geography of West Texas wedged the iconic ASARCO smelter into the geographic center, and later chronology, of her study. To be fair, Grossman demarcated her research to exclude Texas, and ASARCO is the subject of other histories, notably Monica Perales's Smeltertown: Making and Remembering a Southwest Border Community (2010). Still, it may have been beneficial to know if the experience of mining engineers in El Paso supported Grossman's thesis. Geographic limitations aside, Mining the Borderlands is an important study in a region and industry that remain vital to the transnational economies of the United States and Mexico. It will be particularly useful to scholars and students of career specialization and professionalization as well as those interested in the development of cross-border industries prior to the rise of the maquiladora and NAFTA.