On Malvern Hill, the Union rearguard held McClellan's line atop a plateau only 875 yards wide. Confederate batteries were to soften the position before an infantry assault, but the Federal artillery proved superior. As Lee's guns rolled into position, a devastating shower of exploding projectiles overwhelmed them and their crews. Through misunderstanding by Confederate commanders, Southern infantry were ordered to advance across the Carter's Mill Road and up the gentle slope toward the powerful Union position. In 1862, the ground was open farmland in all directions. Wave after wave of Confederates pressed against the Federal line, many to be slain at long range by well-served Union artillery.