This monograph studies the racial integration of Army ground combat units in Eighth (US) Army during the Korean War. The purpose of the monograph is to determine how this change in the utilization of African-American combat soldiers impacted the effectiveness of a US Army organization engaged in fighting a war. This monograph utilizes several methods to accomplish this purpose: study of pertinent records and Army doctrine, primary and secondary source historical analysis, and an inter-disciplinary study of military effectiveness. To answer the primary research question, this monograph also explores in broad terms the origins of the Cold War and US national policy after World War II, the use of Korean soldiers in US Army units during the Korean War, and the Army's segregation policies. This monograph comes to two major findings. First, the integration of African-Americans in Army combat units during the Korean War resulted in improvements in cohesion, leadership and command, fighting spirit, personnel resources and sustainment that increased the combat effectiveness of Eighth (US) Army. Second, contrary to the prevailing Army view, leaders in the Eighth (US) Army held a positive opinion of the ability of African-American soldiers to fight in combat. Both of these findings are evidence of Eighth (US) Army's adaptability.