As the Americans withdrew from the field, they lost all four of their cannons to the British. Two six-pounder guns fired the opening shots of the battle from the center of the first line, and Greene ordered them pulled back to join his other two six-pounders in the defense of the third line. Artillery was important to both armies as supporting fire for infantry. Although mostly ineffective in the heavily wooded terrain that covered much of the battlefield, cannons firing solid shot, grape, and canister were devastating to enemy troops crossing cleared ground.