Julia Young's Mexican Exodus: Emigrants, Exiles, and Refugees of the Cristero War examines the international dynamics of the bloodiest and most protracted religious conflict experienced in the twentieth-century history of Mexico. The Cristero rebellion (1926–9) forced countless refugees across the border into the United States, where they connected with emigrant communities in which they found support for the Cristero cause in Mexico. Young tells the story of these populations and their activism in exile to effect political change in Mexico. Mexican Exodus is a beautifully written and refreshingly accessible addition to the expanding body of literature on the Cristero war. By far, the key innovation and the most important contribution to the vast and ever-expanding body of literature on the Cristero rebellion is Young's contention that exiles, emigrants, refugees and Cristero supporters in the diaspora served to transnationalise the Cristiada. As such, Young quite rightly asserts that we must understand the Cristiada not simply as a Mexican conflict, but as a popular rebellion that transcended national confrontations between the Mexican Catholic Church and the administration of President Plutarco Elías Calles (1924–8).

Young's argument rests on three fundamental premises. The author notes that because Mexican emigration meant that Cristero supporters brought their struggle with them to the United States, the Cristero war necessarily had a much wider geographical impact than scholars have previously assumed. Secondly, Young contends that beyond the interactions between emigrants, exiles and refugees and the Cristeros in Mexico, the conflict connected emigrant communities across regions in the United States as well. The author argues that these intra-national networks were important sources of support for the cause. Finally, Young argues that Mexican emigrants, over the course of the 1920s – an already intense period of emigration from Mexico to the United States – carried with them to the United States their own understandings of the conflict, as well as their identities as political Catholics. Young shows that the Cristiada and the memory of that conflict has passed through generations of Mexican emigrant families, a trend that Young traces into the present. This multigenerational memory of the conflict, its heroes and its martyrs is certainly a phenomenon to which even the casual observer travelling in the Cristero heartland of Jalisco, Guanajuato, Colima and Michoacán might bear witness today.

The author takes care to define the terms that she uses to discuss the various forms of Cristero supporters in the United States. Of course, the use of the word ‘diaspora’ as applied to Mexican emigrants is hotly debated, a point that the author makes very clear. Young's justification for using the term in the case of those individuals and groups fleeing the violence of the Cristiada to the relative safety of the United States is certainly adequate. She uses the term ‘religious’ or ‘Cristero diaspora’. ‘Thus, the Cristero diaspora’, Young asserts, ‘comprised a smaller group within the wider population of Mexican emigrants – all of whom … can collectively be considered a diaspora as well’ (p. 9). The use of the term ‘transnational’, however, is less rigorously interrogated here. It is unclear what makes Young's study transnational, rather than a borderlands study, a study of exile populations, or simply an examination of immigrant communities of the faithful in the United States. In Young's claim that Cristero exiles and immigrant communities transnationalised the Cristero war, there is no attempt to distinguish the author's use of the term ‘transnational’ from the potentially more appropriate ‘internationalisation’ of the movement. What makes this study distinctly transnational in its conceptual framing is less clearly defined.

As a historical study that spans the territory of both Mexico and the United States, Young's archival sources certainly live up to the challenge. The author manages archives in both nations, ecclesiastical and secular, church and state, with aplomb. Young has put together extensive research from the Mexican National Archives, the Archive of the Secretariat of Foreign Relations and myriad archival collections from the Knights of Columbus Supreme Council Archives to smaller private and regional holdings in the United States. Her meticulous archival research allows the author to demonstrate, quite convincingly, the geographic scope of the religious conflict as well as the exile and emigrant networks that supported it on both sides of the border.

In the body of literature treating the Cristero rebellion, regional studies of the conflict, and diplomatic histories of the political intricacies of the war abound. Of course, that body of scholarship is currently expanding with a host of wonderfully nuanced historical perspectives. Young's work represents a singularly important addition to the scholarship that highlights the international dimensions of the conflict affecting communities of the faithful on both sides of the border. Indeed, expanding our field of focus with regard to the Cristiada is an absolute necessity. Young's work establishes a firm, and much needed, foundation on which to build our understanding of the wider geographic dimensions of the Cristero war. Mexican Exodus also holds the potential to illuminate aspects of the state of exile and the movement of peoples in times of conflict on a broader scale, across the twentieth century and, perhaps, into our current historical moment. Mexican Exodus will find a welcome audience among scholars of the Mexican Revolution and post-revolutionary period, religious conflict in Latin America, and, more broadly, immigrant/émigré, diaspora, or exile studies. Young's work is refreshingly clearly written and a much needed addition to the literature on religious conflict in Mexico.