 The battle on Malvern Hill was a resounding Union tactical victory . The victory was due in no small part to Henry Hunt , the Union chief artillerist , who did proficient work in accumulating and concentrating the Union guns . Troop placement before the battle by the army 's principal topographical engineer , Col. A. A. Humphreys , was also carried out capably . The ground on Malvern Hill was used effectively and the Union line had depth with a healthy amount of rested troops available to defend it . Fitz John Porter , the de facto commander for the day , played an important role in this . He posted his men well on June 30 , and stationed reinforcements near to the Union line . Darius Couch , whose forces comprised half of the Union center , positioned his reinforcements skilfully as well and cooperated with George Morell , whose units formed the other part of the Union middle . The infantrymen performed well also . As Brian K. Burton notes , " [ the infantrymen ] stayed behind the guns most of the time and did not advance too far during countercharges . This behavior allowed the gunners a clear field of fire . " Furthermore , if more of anything was needed , infantry or artillery , it was available . At the forefront of the Union victory , however , was the overwhelming firepower of their artillery , as later accounts by soldiers from both armies repeatedly attested . 
