The regiment organized December 27, 1861, at Fort Pillow, Tennessee, officers and men enlisting for twelve months in Confederate service. The Alabama companies have been mentioned as the 7th Alabama Infantry Battalion. Although none of the companies were mounted, some had earlier been attached to Wirt Adams’s Mississippi Cavalry Regiment.

Assuming that a regiment that organized at Memphis was from the State of Tennessee, the War Department initially recognized this command as the 39th Tennessee Infantry Regiment. Once the department recognized the actual composition of Colonel Baker's command, it was renamed the 4th Confederate. However, officers and men referred to it in the field as the 1st Alabama-Tennessee-Mississippi Regiment.

Within a few weeks this unit was directed north to bolster the garrison at Island Ten. There's a good record of the war along the Mississippi River below. The regiment surrendered at Tiptonville, Tennessee, on April 8, 1862, and was exchanged at Vicksburg, Mississippi, September 20, 1862. Orders dated September 29, 1862, dissolved this command. Four companies were directed to the 42nd Tennessee Infantry Regiment, while the remaining six formed part of the 54th Alabama Infantry Regiment