On December 7, the battery was engaged during the Battle of Prairie Grove in Arkansas. During the fight, Roberts' Battery was part of Colonel Robert G. Shaver's brigade, along with several infantry regiments from Arkansas. Shaver's brigade was initially held in reserve, but it was ordered from the Confederate left flank to the right flank by Army of the Trans-Mississippi commander Major General Thomas C. Hindman. Roberts' Battery then moved forward onto a ridge. The battery's new position gave it a clear field of fire against Brigadier General Francis J. Herron's Union division. Of the battery's four cannons, only the two James rifles could be deployed due to the terrain, although the two 6-pounders were still with the battery. The James rifles were the only rifled cannons available to the Confederates at Prairie Grove. After deploying, Roberts' Battery came under heavy Union fire. In turn, the Missourians took up a new position further down the ridge. Even in the new position, heavy Union artillery fire rendered the battery's position untenable, and the guns were withdrawn up the hill. Eventually, Roberts decided that the battery could not hold its position, and the gunners abandoned the pieces and took shelter in some nearby woods. The battery had participated in the fighting at Prairie Grove for two hours, and damaged two cannons of Battery L, 1st Missouri Light Artillery; one shot from the battery wounded a man riding near Herron. The battle ended when night fell, and the Confederates retreated from the field. In order to mask the noises of retreat, the wheels of Roberts' Battery's cannons and caissons were padded with blankets. The retreat continued until the Confederates reached Van Buren, a process that took two days.