In the early hours of June 6, 1944, the 320th Barrage Balloon Battalion, a unit of African-American soldiers, landed on the beaches of France. Their orders were to man a curtain of armed balloons meant to deter enemy aircraft. One member of the 320th would be nominated for the Medal of Honor, an award he would never receive. Drawing on newly uncovered military records and dozens of original interviews with surviving members of the 320th and their...