Lee ordered two “grand batteries” of artillery, one each on his left and right, to envelop the Federal guns in a cross-fire. Poor coordination and effective counter-battery fire from Union guns isolated the Confederate batteries and the desired cross-fire was never effective. The brigade of Brig. Gen. Lewis Armistead was ordered to move forward with the “Rebel yell” to begin the infantry attack once the Confederate artillery had silenced the Yankee guns. Armistead advanced around 3:30 p.m., yet not all the other brigade commanders heard his signal.