This dissertation is the first comprehensive history of American missionaries in the late twentieth century, and the project explores how global missionary networks linked postcolonial changes in the Global South with religiopolitical changes in the United States in mutually constitutive ways. The study has two main arguments. First, the project shows that missionary networks created transnational feedback loops, through which American evangelicals’ experiences from the mission field shaped their changing positions on race, gender, and sex in the United States. Second, the study demonstrates that as the US culture wars matured, missionary organizations exported new conservative policies to international sites, so that some of the New Christian Right’s visions became realities more on the mission field than back home in the US. This project draws on oral histories and never-before-seen internal records from four major missionary organizations, as well as the records of the largest conferences, associations, and seminaries for evangelical missionaries, to demonstrate that the US culture wars emerged out of an international context and played out on an international scale. By tracing the impact of these missionary organizations, which are some of the world’s largest NGOs, this project makes a major contribution to the study of US religion and politics and to the enrichment of North American religious life.