The 20th Alabama spent much of its first year in northeastern Tennessee, and was moved by rail to Mississippi to help defend Vicksburg. The regiment was assigned to Edward Dorr Tracy's Brigade and fought its fight battle at Port Gibson, Miss., May 1, 1863. General Tracy was killed early in that action, and Stephen D. Lee led it at Baker's Creek, May 16, 1863. Col. Ishaw Warren Garrott of the 20th was promoted brigadier general, but was killed in the trenches of the Square Fort at Vicksburg, Miss. on June 17, 1863.
The 20th Alabama surrendered at Vicksburg, Miss. on July 4, 1863. Officers and men were soon paroled and exchanged. After a short time in parole camp, the brigade was rearmed and sent to join the Army of Tennessee outside Chattanooga. Men of the 20th Alabama were involved in the fighting around Craven House on Lookout Mtn. on Nov. 24, 1863, and defended Missionary Ridge the following day.
After passing winter camp at Dalton, GA, the regiment were involed in the following actions in the Atlanta Campaign:
Demonstration against Rocky Face Ridge, Georgia May 9, 1864.
Battle of Resaca, Georgia May 14-15, 1864.
Combats near Cassville, Georgia May 18-19, 1864.
Battle of New Hope Church, Georgia May 25, 1864.
Combats at and about Ackworth, Georgia May 26-June 4, 1864.
Combat at Kolb’s Farm, Georgia June 22, 1864.
Operations about Marietta, Georgia June 10-July 2, 1864.
Operations about Smyrna, Georgia July 3-5, 1864.
Operations along the Chattahoochee River, Georgia July 6-9, 1864.
Battle of Atlanta, Georgia July 22, 1864.
Siege of Atlanta, Georgia July 29-August 26, 1864.
Battle of Jonesboro, Georgia September 1, 1864.
The regiment was also involved in crossing the Duck River at Columbia, Tenn. Nov. 29, 1864, the Battle of Nashville, Tenn., Dec. 15-16, 1864, and the retreat south across the Tennessee River. It participated in the Battle of Bentonville NC, Mar. 19-21, 1865, and surrendered at Salisbury NC, May 2, 1865.
I've left out several events that should be mentioned, but I'm sure others can fill in the gaps.