The U.S. Army has long used the staff ride as a tool for professional development, conveying the lessons of the past to contemporary soldiers. In 1906 Maj. Eben Swift took twelve officer-students from Fort Leavenworth’s General Service and Staff School to the Chickamauga battlefield on the Army’s first official staff ride. Since that time Army educators have employed staff rides to provide officers a better understanding of past military operations, of the vagaries of war, and of military planning. A staff ride to an appropriate battlefield can also enliven a unit’s esprit de corps—a constant objective in peacetime or war. To support such Army initiatives, the Center of Military History publishes staff ride guides, such as this one on the Battle of First Bull Run. This account is drawn principally from contemporary after action reports and from the sworn testimony of participants before the Joint Committee on the Conduct of the War, a congressional entity created to investigate the Union defeats at First Bull Run and Ball’s Bluff. A First Bull Run staff ride can offer significant military lessons. Revisiting this battle through the “eyes” of the men who were there, both leaders and rank-and-file soldiers, allows one insights into decision making under pressure and the human condition during battle. The campaign contains many lessons in command and control, communications, intelligence, logistics, the accommodation of advances in weapon technology, and mobilization in the absence of universal military training. First Bull Run was a first battle—a major engagement after a prolonged period of peace. For some it constitutes a metaphor of the price paid for military unpreparedness. Hopefully, this volume will prove a useful tool for those conducting a staff ride to First Bull Run