Many religious leaders in the early 1900s were afraid of the immoral associations and repercussions of birth control. The Catholic Church and some Protestants never accepted contraception, or accepted it much later, but many mainline Protestants leaders did change their tune dramatically between the years of 1920 and 1931. This investigation seeks to understand how Margaret Sanger was able to use her rhetoric to move her reform from the leftist outskirts and decadent, sexual connotations into the mainstream of family-friendly, morally virtuous, and even conservative religious approval. Securing the approval of religious leaders subsequently provided the impetus for legal and medical acceptance by the late-1930s. Margaret Sanger used conferences, speeches, articles, her magazine (Birth Control Review), and several books to reinforce her message as she pragmatically shifted from the radical left closer to the center and conservatives. She knew the power of the churches to influence their members, and since the United States population had undeniably a Judeo-Christian base, this power could be harnessed in order to achieve success for the birth control movement, among the conservative medical and political communities and the public at large. Despite the clear consensus against birth control by all mainline Christian churches in 1920, including Roman Catholics and Protestants alike, the decade that followed would bring about a great divide that would continue to widen in successive decades. Sanger put forward many arguments in her works, but the ones which ultimately brought along the relatively conservative religious leaders were those that presented birth control not as a gender equity issue, but rather as a morally constructive reform that had the power to save and strengthen marriages; lessen prostitution and promiscuity; protect the health of women; reduce abortions, infanticide, and infant mortality; and improve the quality of life for children and families. Initially, many conservatives and religious leaders associated the birth control movement with radicals, feminists, prostitutes, and promiscuous youth, and feared contraception would lead to immorality and the deterioration of the family. Without the threat of pregnancy, conservatives feared that youth and even married adults would seize the opportunity to have sex outside of marriage. Others worried the decreasing size of families was a sign of growing selfishness and materialism. In response, Sanger promoted the movement as a way for conservatives to stop the rising divorce rates by strengthening and increasing marriages, and to improve the lives of families by humanely increasing the health and standard of living, for women and children especially. In short, she argued that birth control would not lead to deleterious consequences, but would actually improve family moral values and become an effective humanitarian reform. She recognized that both liberals and conservatives were united in hoping to strengthen the family, and so she emphasized those virtues and actively courted those same conservative religious leaders that had previously shunned birth control and the movement. Throughout the 1920s, she emphasized the ways in which birth control could strengthen marriages and improve the quality of life of women and children, and she effectively won over the relatively conservative religious leaders that she needed to bring about the movement’s public, medical, and political progress.