||religious thought and practice that is American in origin. From a beginning in western New York in 1830 it has grown into an organization which is worldwide in scope. Those largely responsible for this expansion are Mormon missionaries- members of the Church who devote two to three years in voluntary proselyting service in the interest of their faith. In many ways the missionary system has become one of Mormonism's most powerful institutions. This study will trace the history of Mormon missionary expansion into South America up to 1940. The term South America in this thesis designates primarily the area of Brazil and Argentina. This is where the first significant Mormon advances were made in this part of the world. Chile is mentioned in the early chapters and other South American countries are discussed as Mormons came in contact with them. Throughout the chapters of this thesis the author has attempted to illustrate not only the growth of the Mormon church, but also the proselyting methods, procedures, mission policies and particular problems that have faced the missionaries during the years when Mormonism was struggling to gain a foothold in South America. Chapter III, giving the religious background in Argentina and Brazil, was written for the purpose of helping the reader visualize the e c c l e s i a s tical atmosphere in which Mormonism was established. The chief sources of material for this study have been books and periodicals published by the Mormon church, letters of missionaries, quarterly historical reports V and financial and statistical reports from the missions, autobiographies, journals, mission publications and private interviews with former missionaries to Brazil and Argentina. This study includes no data concerning the members of the Church in South America, how they were converted to this American religion or their problems in accepting its doctrine and staying true to it. It has not been possible to get any source material which would illustrate a view of the Mormon church through the eyes of a Brazilian or an Argentinean. Because few Mormons have emigrated to the United States from the missions of the Church in South America there are no available journals, diaries or documents of these emigrants which describe the reactions of those who have been the recipients of this proselyting expansion. This study, therefore, is limited to the North American Mormon missionaries' view of their own activities. In this thesis, the Church of Jesus Christ of Latter-day Saints is referred to frequently as "the Church. " This is done for the purpose of avoiding the use of this long proper name or the repetition of the word "Mormon. "