The regiment was brigaded under McLaws, Semmes, and Corse, Army of Northern Virginia.

It fought with the army from the Seven Days' Battles to Fredericksburg, then was involved in Longstreet's Suffolk Expedition.

During the Gettysburg Campaign, the 15th was on detached duty, and after serving in Tennessee and North Carolina participated in the battles at Drewry's Bluff and Cold Harbor.

Later it took its place in the Petersburg trenches north and south of the James River and ended the war at Appomattox.

This unit contained 476 effectives in April, 1862, reported 1 killed and 8 wounded at Malvern Hill, and lost fifty-nine percent of the 128 engaged at Sharpsburg.