Many Christians, especially in the United States, believe that they and their fellow believers will soon vanish from the earth in an event called "the rapture." The rapture is one feature of a complex theological system called dispensationalism. Dispensationalism was developed an Irish dissenter named John Nelson Darby in the 1830s, but it only began to attract a mass following in the United States in the 1870s. This dissertation examines the development of American dispensationalism in the period before it attracted a substantial following. It shows that dispensationalism was developed as a challenge to the culturally conditioned religion of American evangelicals. Dispensationalist eschatology, which predicted the apostasy of the church and the removal of true Chrsitians from the earth, encouraged believers to distance themselves from their ociety and to avoid political or social power.