What is the nature of openness, and what role has it played in education over the years? The concept of openness has traditionally been very difficult to define, and its history in education has often been ignored, obscured, or misrepresented in the literature, media, and popular culture. This paper provides an operational definition of openness and highlights the history of openness in education over the last century. This serves as a useful lens for better understanding the nature of openness and from which to examine the role of openness in education in new ways. This history legitimizes openness as an approach to education with historical significance, and establishes a precedent for certain types of instructional strategies and educational models that are common today. The paper concludes with a push for educators to continue thoughtfully integrating openness within the current educational system in a practical, experimental way. This will continue the integration of these systems and result in one that retains the strengths of both traditional and open approaches.