<p> Altruism is an imperative for nursing practice and education, but no research has explored its meaning using a historical method. This study aimed to explicate the meaning of altruism through the study of four Southern Baptist nurse missionaries. Ruth Kersey, Amanda Tinkle, Hazel Moon, and Helen Masters served in Nigeria between 1920 and 1981. Their correspondence archives were used as primary sources of data and analyzed for examples of altruism. These women founded orphanages and leprosy treatment programs, and managed clinics and hospitals run by the Southern Baptist Church in Nigeria. Additional interconnected variables of race, gender, and religion were also found to influence their work. The findings of this study supported altruism as a sacrificial behavior motivated by benefiting others. Nursing&rsquo;s presence in global health, its expansion in leadership, and its future identity are supported by the study of these four nurses. Further research into the work of nurse missionaries in nursing&rsquo;s past is recommended to increase the understanding of missionary work and altruism.</p><p>