This book project proposes to deepen our understanding of migration, religion and transnationalism through a focused examination of the growth of Pentecostalism in the U.S.-Mexico borderlands in the early to mid-twentieth century. It traces the evolution of Mexican/Chicano Pentecostalism through the first decades of growth (1906-1966), and examines the construction of transnational circuits and webs that bolstered subaltern responses to macro events and prejudicial actions of nation-states and majority cultures. The project proposes to map the early history of the movement through a focused study of religious genealogies (congregational, regional, and individual) that spread and took root along the borderlands swath stretching from the Pacific Coast to the Texas-Tamaulipas border and deeper into both countries. This study will provide useful analytical templates (e.g., the border as trampoline and creative zone) for understanding Pentecostalism’s explosive success in later decades throughout further flung regions in the hemisphere. By providing a historical context, it brings a long overdue attention to linkages and genealogies to discussions of contemporary evangélico growth among U.S. Latinos and in Latin America, demonstrating the continuities and discontinuities with prior historic Protestant expansion and the even older Spanish Reform project. In Mexico and the U.S. Southwest, as elsewhere in Latin America, Pentecostal and Pentecostal-like religious practices migrated more easily than others because they required less institutional support and management.  Consequently, they emerged as prime carriers of the culture, flowing along the fissures created by the large-scale economic, political and social transformations of the twentieth century. A vibrant religious musical culture tied these expanding transnational communities as much as did more material elements.