Later in September 1862, the 89th was sent to Western Virginia (today West Virginia) to reinforce Union forces there, and joined in their advance for a month. The regiment settled into winter quarters, but was called out for transport to Tennessee, where it helped relieve Fort Donelson in February 1863. Before this action, Foraker had seen little fighting, and the bloody scenes there were a shock to him; he wrote his parents, "To know how dreadful war is you must see it yourself." The 89th remained at Donelson only a few days before being sent to join the Army of the Cumberland under the command of Major General William Rosecrans near Carthage; there, Foraker was promoted to second lieutenant. In June, Foraker led an advance guard that clashed with the Confederate rear in what developed into the Battle of Hoover's Gap, and the Union forces slowly advanced across Tennessee, reaching Chattanooga in September. From Chattanooga, Foraker and two other officers were sent home to collect new soldiers who were expected to be drafted, but the plan to draft recruits was abandoned due to political opposition. In November he returned to Chattanooga, where the 89th was now part of the Army of the Tennessee under Brigadier General William Tecumseh Sherman, in time to fight in the Battle of Missionary Ridge.