In the latter part of the nineteenth century, Mary Sheldon Barnes emerged as a leading historical methods professor and history textbook author. Although men dominated the field, she wrote several articles and books alone or with her husband Earl Barnes about primary source materials and teaching. She lived during an era in United States history when education was evolving. Students studied traditional subjects such as grammar, mathematics, and Latin using rote memorization. Students who failed to learn classroom material faced varying degrees of punishment from teachers. Classroom pedagogy in the nineteenth century was teacher-focused and teachers often employed a considerable amount of physical fear. Mary Sheldon Barnes developed her pedagogy and writing style using scientific history and German seminary style classrooms. As a teacher, she taught in a normal school, gender specific college, and a co-educational institution of higher learning and these experiences impacted her pedagogy. Barnes rejected the regimented, teacher-centered, memorization/recitation pedagogy of the nineteenth century. She preferred a teaching style that provided more student-centered, discussion-oriented history pedagogy. This study utilizes biography as a format to explore Mary Sheldon Barnes as a pioneer teacher and author. Following her death, history textbook authors turned away from source material textbooks back to traditional chronological design and ignored her contributions to social education history. This dissertation provides an examination of her life and explores its influence on contemporary textbooks and pedagogy. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]