This chapter first traces the historical framework of Mormon conversion in the nineteenth-century church forward into the twentieth century. Next, it analyzes the reorganization of the mission program and the church administration through the 1960s Correlation program. Subsequent sections on contemporary conversion and retention efforts in Mormonism follow a geographical approach, dealing first with the United States and subsequently with Latin America, Europe, Africa, and Asia. The conclusion develops ideas on Mormon conversion and traces the origin of the current low retention rates in developing countries to the new policies of the 1960s. More recent changes in mission policies were defined in 1985 and 2004, which consequently had a substantial impact on missionary and convert recruitment.