Reviewed by: Borderlands of Slavery: The Struggle over Captivity and Peonage in the American Southwest by William S. Kiser Lauren Brand (bio) Borderlands of Slavery: The Struggle over Captivity and Peonage in the American Southwest. By William S. Kiser. (Philadelphia: University of Pennsylvania Press, 2017. Pp. 280. Cloth, $47.50; paper, $24.95.) Could slavery in any form expand into the American West? Was it realistically possible? Did the U.S. government have the right to regulate the expansion of slavery? These are some of the massive questions that dominated the political discourse of the antebellum United States. William S. Kiser’s Borderlands of Slavery explores how the reality of Native captivity and debt peonage in New Mexico played a crucial role in the answers that both northern and southern politicians offered to these questions. New Mexico not only shaped national conversations about slavery’s expansion in the antebellum era, but also influenced national policy makers’ decisions regarding the definition of unfree labor during the Reconstruction era. Kiser argues that the existence of a different form of slavery in New [End Page 248] Mexico “forced Americans to think more broadly about slavery and brought awareness to the fact that involuntary labor was not limited to the chattel system in the South” and that this realization “informed profound political debates during the 1850s regarding the future role of unfree labor in the country” (21). The prologue provides a concise overview of the history of New Mexico from the Spanish colonial era through the territory’s integration into the United States in the mid-nineteenth century in order to quickly familiarize readers with this complex period. Indeed, scholars from many subfields of nineteenth-century United States history will find much of interest in this short book. For example, historians studying the various forms of enslavement endured or practiced by the Indigenous peoples of North America (or “the other slavery,” as Andrés Reséndez describes it)1 will appreciate Kiser’s description of the widespread prevalence of Native captivity in New Mexico from the Spanish colonial era through the Civil War. Additionally, historians of the antebellum U.S. South will be interested in Kiser’s dissection of how southern politicians used New Mexico and the various forms of captivity there as a foil to compare to the southern system of enslavement. Although debt peonage was not a racially based system of enslavement, it was a structure that “nonetheless operated upon manipulated conditions of dependency that typically ensured perpetual bondage” (16), leading many southern congressmen to view New Mexico as a valid point of comparison to demonstrate the compatibility of slavery with peonage in the American West. Kiser shows throughout that such comparisons were not unwarranted. For example, he explores comparisons between the ways captive women in the Southwest were described as “likely girl[s]” and valued for their attractiveness and sexual availability in the same way that African American women were in the South (61). However, despite some similarities that prompted these comparisons, Kiser notes that, in the end, there remained “widespread confusion about the differences between Southern slavery and New Mexico’s traditional forms of bondage . . . among federal lawmakers” (52). State and local historians will also appreciate Kiser’s attention to the perspectives of people actually living in New Mexico during this period. Kiser explains how residents of New Mexico themselves thought about these issues. For example, he notes that local people were somewhat ambivalent about chattel slavery and the comparison to the U.S. South but remained just as concerned about retaining their rights to captives and peons as they always had. Kiser also explores how, after 1846, local New Mexico law-makers purposely kept quiet about the issue of debt peonage, because they often personally benefited from it. Thus Kiser notes how challenging it can [End Page 249] be for historians to study the ways captivity and debt peonage impacted the lives of people in New Mexico. The sources have to be carefully mined to reveal what was really going on behind the surface. Kiser is very open about these challenges and how he reads the available sources. As time passed and sectionalist sentiment increased in both the United...