Higher education historians agree that the earliest direct antecedents to today's student affairs professionals were deans of women (DOWs) and deans of men (DOMs), administrative positions that first arose in the 19th century. While DOWs were expected to supervise women students within newly coeducational environments, they professionalized the role - and the field of student affairs - by building professional networks, conducting scholarship, and pursuing graduate education. This historical study used archival records to explore the earliest student affairs graduate program, a professional diploma for DOWs at Teachers College, Columbia University, started in 1914. Findings explore the development of the diploma program throughout its lifespan, including its origins and the Teachers College context, diploma name changes, the first program-specific courses, and curricular changes. The Teachers College DOW professional diploma program ran for 30 years, ending after the 1944-45 academic year. This research provides insight into the history of student affairs as a field of study and illustrates the field's long-standing values and philosophy, particularly the importance of supporting and advocating for minoritized students (ACPA, n.d.). Student affairs scholars and practitioners can use this history to better understand and articulate the context and purpose of their work today.