Early in the Tullahoma Campaign, Union forces in the Army of the Cumberland advanced upon a series of gaps south of Murfreesboro occupied by the Confederate Army of the Tennessee. In a series of attacks and counter-attacks that followed including the 39th Indiana Infantry armed with Spencer repeating rifles, the Confederate forces withdrew to Tullahoma.
Calhoun
On September 25, 1863 the First Brigade of Col. R.K. Byrd (Fourth Division, 23rd Corps) was attacked by Confederate forces