In mid-September 1862, in response to the offensive by Confederate Generals Earl Van Dorn and Sterling Price, a three company battalion of the Sharpshooters marched south with Major General Rosecrans' army towards Iuka, Mississippi. This detachment participated in the September 19th battle. They then returned to Corinth, where the entire regiment fought on both days of the October 3rd-4th (2nd) Battle of Corinth. On Oct 4th, as per General Rosecrans' orders, the regiment fought as skirmishers in the timber in front of the Federal fortifications (to the right of a 3 company battalion of the 64th Illinois ["Yates' Sharpshooters"]). They skirmished under the direct command of Colonel Burke from 4 a.m. to around 10 a.m., when they began to fall back on the main Federal line. When the Federal center collapsed, the regiment fell back again towards the town and Battery Robinette, where they continued to fight until the Confederate breach was contained.