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 supervision of fortifications and weaponry surrounding Washington, D.C., Barry took on the role of chief of artillery under Major General William T. Sherman. They worked together during campaigns in Tennessee, the March to the Sea, and the Carolinas.