This work reconstructs the history of Mexico’s forgotten “Religionero” rebellion of 1873–1877, an armed Catholic challenge to the government of Sebastián Lerdo de Tejada. An essentially grassroots movement—organized by indigenous, Afro-Mexican, and mestizo parishioners in Mexico’s central-western Catholic heartland—the Religionero rebellion erupted in response to a series of anticlerical measures raised to constitutional status by the Lerdo government. These “Laws of Reform” decreed the full independence of Church and state, secularized marriage and burial practices, prohibited acts of public worship, and severely curtailed the Church’s ability to own and administer property. A comprehensive reconstruction of the revolt and a critical reappraisal of its significance, this book places ordinary Catholics at the center of the story of Mexico’s fragmented nineteenth-century secularization and Catholic revival.