This unit was part of Colonel Abner Monroe Perrin's First Brigade[6] of a division commanded by General William Dorsey Pender.
Miller first led this unit at the Battle of Chancellorsville, and in the aftermath of this significant Confederate victory, was assigned to March 2000 Union prisoners to Richmond, Virginia.
[7] Although his regiment had 20 men killed at Gettysburg, Miller survived the defeat and helped organize the Confederate retreat.
In the days that followed, the 12th Regiment lost another 18 men killed in the Battles of Hagerstown and Falling Water during the retreat from Gettysburg.
It was said that he "commanded the respect of officers and men by his courage and conscientiousness, and acquired many friends by his affable and courteous deportment".