After later supervising forts and ordnance surrounding Washington, D.C., Barry became chief of artillery under Maj. Gen. William T. Sherman, serving with him in Tennessee, the March to the Sea, and the Carolinas Campaign.
Following his role in managing defenses around Washington, D.C., Barry took on a position as chief of artillery under General Sherman during key campaigns like those in Tennessee, the March to the Sea, and the Carolinas.