3rd Regiment, Alabama Reserves
Overview: 3rd Reserve Regiment, organized during the summer of 1864, was composed of very young men. Stationed at Mobile, it served in General B.M. Thomas' Brigade, District of the Gulf. In February, 1865, the unit was ordered to Selma. Six companies were assigned guard duty at the post of Cahaba, and in March attached to General Clanton's command. It was reported to be at Montgomery during April with approximately 300 effectives, and in May was included in the surrender of the department of Alabama, Mississippi, and East Louisiana. Colonel William M. Brooks, Lieutenant Colonel W.D. Bulger, and Major Whitfield Walker were in command.
I found this about the 3rd regiment...it was started in 1864 so i don't know if the one that EllinSpain found is correct