Lifestyle Medicine (LM) is a rapidly growing discipline that focuses on the role of lifestyle factors in preventing, managing, and reversing chronic disease. At this point in the field's evolution, there is strong evidence that the 6 pillars of LM-a whole-food, plant-predominant eating pattern, physical activity, restorative sleep, stress management, avoidance of risky substances, and positive social connections-are central in the creation and maintenance of health. Previous publications, many of them randomized controlled studies and meta-analyses, have solidified the evidence base for the use of the 6 pillars within the field of LM. As data emerged, so did its governing body, the American College of Lifestyle Medicine (ACLM), and with it a rich history began to unfold. Several articles have been written on the early history of the ACLM and the growth of the field; however, this review article explores the history and foundation of LM, aiming to provide a comprehensive understanding of its relevance and impact on health care. It underscores landmark studies that have defined the field and provides a road map detailing national and global barriers and areas of potential future growth.