"Soldier's Heart" is a historical term used to describe the psychological trauma experienced by soldiers during and after the American Civil War. It is now recognized as an early form of what we call post-traumatic stress disorder (PTSD). Symptoms included anxiety, nightmares, and emotional distress, which affected many veterans returning home. The condition was often misunderstood at the time, leading to stigma and inadequate treatment options. Efforts to address "Soldier's Heart" laid the groundwork for modern understanding of mental health issues in military personnel, highlighting the importance of psychological care for those who serve in combat.