50th (Old) Infantry Regiment was organized at Fort Donelson, Tennessee, in December, 1861. Its members were raised in the counties of Montgomery, Dickson, Cheatham, Stewart, Humphreys, and Davidson. In January, 1862, the unit reported 499 present for duty and about half were captured at Fort Donelson in February. After being exchanged and reorganized, it was assigned to J.Gregg's Brigade, Department of Mississippi and East Louisiana, and fought at Chickasaw Bayou, Raymond, and Jackson. The 50th then took an active part in the Battle of Chickamauga. Before it participated in the conflict at Missionary Ridge, the unit was transferred to General Maney's Brigade and in February, 1864, reorganized as the 50th (New) Tennessee Regiment. It lost seventy-four percent of the 190 engaged at Chickamauga and forty percent of the 90 at Missionary Ridge. During December, 1863, it totalled 90 men and 52 arms. The field officers were Colonels George W. Stacker and Cyrus A. Sugg, Lieutenant Colonels T.W. Beaumont and Harrison C. Lockhart, and Major Christopher W. Robertson.

50th (New) Infantry Regiment was formed in February, 1864, by consolidating Colms' 1st Tennessee Battalion and the 50th (Old) Tennessee Regiment. It was assigned to Maney's and Palmer's Brigade, Army of Tennessee, and participated in the Atlanta Campaign, Hood's winter operations, and the North Carolina Campaign. The regiment surrendered on April 26, 1865, with 37 men. Colonel Stephen H. Colms and Lieutenant Colonels O.A. Bradshaw and George W. Pease were in command.