From 1863 to 1865, the regiment remained in Arkansas, going on expeditions to suppress Confederate raiders and other occupation duties.

After the Battle of Prairie Grove the regiment was ordered to occupy the town of Huntsville, Arkansas.

On January 10, 1863, nine southern men who had been detained for some days for reasons unknown were ordered executed by Lieutenant Colonel Elias Briggs Baldwin, for reasons that still today are unclear.

At the time of the incident, most of the regiment had moved on toward the Mississippi River with only a small detachment remaining in Huntsville.

Baldwin would later be arrested for the murders and transported back to Springfield for trial, but due to witnesses being displaced or otherwise unable to make the trip to Springfield, and the members of the regiment who were present during the event being on active duty elsewhere, Baldwin was released with the charges dropped and dismissed from the army.

By the time Baldwin was arrested, the 8th Regiment was on the move in pursuit of Confederate Major General Sterling Price.

They spent the remainder of the war securing Arkansas, during which time they engaged Confederate forces and Guerrilla bands in several minor skirmishes, but with no major actions.

Attached to 2nd Brigade, 3rd Division, Army of the Frontier, Dept.

1st Brigade, 1st Cavalry Division, District of Southeast Missouri, Dept.

3rd Brigade, Cavalry Division, 7th Army Corps, to February, 1865.

2nd Brigade, Cavalry Division, 7th Army Corps, to March, 1865.

1st Separate Cavalry Brigade, 7th Army Corps, to July, 1865.

Join Davidson's Division at Pilot Knob, Mo., June, 1863, and march to Clarendon on White River, Ark.