Army of Georgia
He was promoted to major general on August 12, 1864, and General Sherman ordered Mower to join the Union forces in Atlanta. He commanded the 1st Division of the XVII Army Corps during the March to the Sea and the Carolinas Campaign. His division played a significant role in the battles of Salkehatchie and Bentonville. Sherman made him commander of XX Corps in the Army of Georgia late in the war. After the fighting had ceased he sailed for Texas along with General Gordon Granger. He was placed in command of the District of Eastern Texas.