As a brigade commander in the Atlanta Campaign in 1864, he fought at Resaca, New Hope Church, and Kennesaw Mountain, Georgia. He was appointed and confirmed as brigadier general of volunteers on June 22, 1864, leading the 2nd Division. He participated in the Siege of Atlanta, and then transferred to the XV Corps, where he served through the March to the Sea and the Carolinas Campaign. Rice was mustered out of the volunteers on August 24, 1865. On January 13, 1866, President Andrew Johnson nominated Rice for appointment as a brevet major general of volunteers for war service to rank from March 13, 1865 and the United States Senate confirmed the appointment on March 12, 1866.