The Maryland Heights portion of Elk Ridge was the scene of much activity during the American Civil War. Artillery emplacements and fortifications were first erected on the mountain by Union forces in 1862, during Stonewall Jackson's Valley Campaign. Later that year, during the Battle of Harpers Ferry, the union fortifications on the mountain were attacked by units under General Lafayette McLaws, who subsequently took control of the ridge and used it to deliver devastating artillery fire against the Union garrison at Harpers Ferry. After the battle Confederate forces abandoned the ridge to rejoin the Army of Northern Virginia at Antietam and the Union army quickly reoccupied the heights.