Colonel John W. Fuller's Ohio Brigade left Huntingdon well before dawn on December 31. When just north of Clarksburg, around 10:30 a.m., Fuller received orders from Generals Jeremiah Sullivan and Isham Haynie to wait for the rear guard before resuming the march.
Soon afterward, Fuller learned that an enemy patrol had attacked the generals and their escort. Fuller quickly marched toward Clarksburg, where he learned that an enemy patrol had attacked the generals and their escort. Fuller quickly marched toward Clarksburg, where he learned that Dunham's brigade had left some hours earlier. After a ten-minute wait with no word from Sullivan or Haynie, Fuller pressed southward. The brigade had not advanced far when they heard cannonading.
Fuller was within two miles of Parker's Crossroads when he received orders to wait for Sullivan, who was three miles behind him and coming up quickly with the rear guard. Fuller explained the situation to the brigade adjutant, telling him to hurry to Sullivan and request the general countermand his orders. Soon thereafter, Fuller received confirmation that a large Confederate force was between his brigade and Dunham's. Fuller immediately moved south, convinced that Sullivan would approve.
Fuller's Brigade advanced to the battlefield and took position as flags of truce were being passed near the split-rail fence. The 27th and 63rd Ohio formed on the left of the Lexington-Huntingdon Road, the 39th Ohio on the right, while the 7th Wisconsin Battery readied their three cannon on the ridge in front of you. Their approach went unnoticed by the Confederates, who were intent upon watching Dunham's brigade, now split into two isolated remnants, and the Union surrender that appeared to be taking place.
The Ohio Brigade attacked the Confederate gunners and infantry from the rear. Two Union cannon were moved to a position in front of the Parker house while the third, placed west of the road, poured a barrage of shot and shell on the fleeing Confederates. The horseholders of Cox's battalion took the brunt of the initial infantry assault and broke ranks, stampeding in panic. The Confederate victory, so certain just moments before, dissolved in the face of Fuller's timely assault.