A broad and accessible history of religion in Texas, from prehistory to the present. From sprawling megachurches to religious billboards and towering steel crosses, religion quite literally looms over Texas. Christian nationalism determines the state's politics and, every school day, more than five million Texas children pledge allegiance to "one state under God." But it wasn't always this way. In this wide-ranging chronicle, Joseph Locke uncovers the breadth of Texas's religious history, from Indigenous painters of cosmological cave art and Spanish invaders who constructed missions, to irreligious Anglo colonists, freethinking frontiersmen, Tejano folk saints, evangelical culture warriors, and Muslim immigrants. Locke traces the state's religious transformations across the centuries, bringing them to life through his depiction of compelling figures, like enslaved preacher Anderson Edwards, fighting fundamentalist J. Frank Norris, and celebrated humanitarian Sister Norma Pimentel, and gripping moments, such as the murder of atheist newspaperman William Cowper Brann and the siege of the Branch Davidian compound in Waco. Comprehensive, fast-paced, and highly readable, One State Under God reveals how the Lone Star State's spiritual path was blazed.