In April, the new 10th, now under the command of Col. Robert A. Smith and numbering only 360 men, fought in the Battle of Shiloh in West Tennessee. It later participated in Braxton Bragg's Kentucky Campaign and suffered significant casualties at the Battle of Munfordville, including Colonel Smith. Chalmers' Brigade, including the 10th Mississippi, was part in the advance toward Louisville in September. Under Col. James Barr, Jr., the 10th fought in the Battle of Perryville before retreating with Bragg's beaten army across the Cumberland Gap on October 20. Marching through Tennessee, the regiment camped near Murfreesboro, Tennessee, in November. It fought in the subsequent Battle of Stones River in late December and early January 1863.