The 19th was initially understrength, having only eight of its required ten companies; the remaining two joined on 11 December to bring it to a strength of 873 men.

[2] The ten companies, hailing from north Louisiana, were as follows:[3] Caddo Parish lawyer Benjamin Lewis Hodge of the Keachi Warriors was elected colonel, De Soto Parish planter James M. Hollingsworth of the Henry Marshall Guards lieutenant colonel, and Shreveport lawyer Wesley Winans of the Caddo 10th major.

From July, it served as part of the garrison of Mobile, Alabama, encamped at Pollard east of the city.

[3] Returning to the Army of Tennessee in north Georgia, the regiment and its brigade fought in the Battle of Chickamauga between 19 and 20 September.

In the Battle of Missionary Ridge on 25 November, the 19th repulsed several attacks but was forced to retreat when outflanked by the Union advance.