Positioned 300 feet above the Potomac River the Naval Battery was the first Union fortification on Maryland Heights. Hastily built in May 1862, its naval guns were rushed here from the Washington, D.C., Navy Yard. Along with a detachment of 300 sailors and marines, the battery was equipped to protect Harpers Ferry from Confederate attack during Stonewall Jackson's famous Valley Campaign in the spring of 1862.
Thwarted that spring, Jackson returned to Harpers Ferry in mid-September 1862, during the Confederacy's first invasion of the North. Jackson's three-day siege included an infantry battle on the crest of Maryland Heights on September 13, in which the Confederates advanced south along the ridgetop. The Naval Battery guns were turned uphill to pound the crest, but orders to retreat forced the Federals to abandon the mountain and this battery.
On September 22, one week after the Union surrender at Harpers Ferry, U.S. forces returned to Maryland Heights to build fortifications at better locations on the crest and slope of the Heights. The Naval Battery lost its defensive importance and eventually became an ordnance depot.