The purpose of AECT at 100: A Legacy of Leadership is to highlight the Association for Educational Communications and Technology’s 100 years of leadership in educational technology and learning. AECT has a rich history, evolving from the National Education Association’s (NEA) Department of Visual Instruction (DVI) and later the Department of Audio-Visual Instruction (DAVI). Over its 100 years, AECT and its members have had a substantial impact on the evolution of American educational technology and learning, including in the areas of audiovisual instruction, instructional design, and online learning. AECT at 100: A Legacy of Leadership brings together writers and experts in the organization to explore various periods of history within the field and how AECT and its membership stood as a leader within the field. Topics such as visual instruction, the audiovisual movement, leadership development, programmed instruction, diversity leadership, AECT and educational technology topics, journals, ethics, and social justice are explored. Additionally, a number of leaders are explored from the early days of AECT such as James Finn, F. Dean McClusky, Edgar Dale, and Elizabeth Golterman all the way to recent leaders such as Rob Branch.