Samuel A. Duncan was a Union soldier during the Civil War and Colonel (at various times) of the 4th, 5th, 6th, and 22d Colored regiments. (All officers were white.) He and his troops were part of the attempt to storm Richmond and release Union prisoners, but it was foiled when a deserter gave the plan away to the Confederates. When the Confederates decided that captured African-American troops would be reduced to slavery, Duncan proposed using captured Confederates for hard labor in retaliation, but he was overruled. His men took part in the storming of Petersburg and the battle of New Market Heights, although he was wounded in the fighting and John W. Ames then lead them.