Before moving up to the crest, there are two earthwork traces worth mention. First a mortar battery sat about 200 yards to the rear of the 30-pdr Battery, and leaves us a shallow pit today to remember it by. Second a line of what appear to be rifle pits extend across the heights about 300 yards to the rear of the 30-pdr Battery. This looks as a rudimentary tertiary line of defense across the heights, and not as extensive as the other works.
The first of fortifications at the military crest of the heights is perhaps the most interesting to me. The 100-pdr Parrott Battery was sited to allow firing both up and downstream on the Potomac and upstream on the Shenandoah. The battery could also clear Loudoun and Bolivar Heights, and in theory School House Ridge. The siting of the gun allowed it a clear view of South Mountain and Weaverton along the river. Visitors today should imagine the crest of the mountain almost devoid of trees here, as a result of both charcoaling and military operations. Thus affording the massive rifle nearly an all around firing arc (where today trees block much of the view).
The NPS marker indicates the Parrott was mounted on a pintle barbette carriage. Thus in operation, this piece looked very similar to the often reproduced photo of the 100-pdr at Fort Totten, Washington D.C. In place, this was the highest elevation of any large caliber siege and garrison artillery east of the Mississippi (if not the whole continent!) . In this writers opinion, the story of the 1st Massachusetts Heavy Artillery, attributed as erecting this monster at this height, deserves attention. The tube alone weighed nearly five tons. Add to that the carriage, sandbags, planking, etc. Plus a quantity of 100 pound shells and powder. The feat would not be a simple chore even today with power equipment.
When initially built, the 100-pdr Parrot was not placed. Instead a IX-in Dahlgren (logically one of those used at the Naval Battery down the slope) was placed. At the time of the Gettysburg Campaign, if the battery was functional, it was the Admiral’s gun at the top of the mountain. The Parrott arrived in August 1863.
The Parrott had a bore of 6.4 inches, and weighed in the neighborhood of 9750 pounds. The piece, like all Parrotts, had a massive reinforcing band around the breech. Unlike the smaller army series West Point Foundry products, these and larger Parrotts had a breech block type cascabel instead of a knob, making it almost indistinguishable from Navy pieces of the same caliber. Of 233 produced for the Army between 1861 and 1865, just over 50 survive today. (The Navy received 352 similar pieces, and under twenty exist.)
The impressive figure aside from the weight is the range of shell – 6820 yards at 25 degrees elevation. Shot is listed as 8453 yards at 35 degrees elevation. Roughly 3.8 miles for shell and 4.8 miles for shot. This means the big Parrot on top of Maryland Heights could hurl solid shot projectiles down stream to Berlin (now Brunswick), MD where pontoon bridges spanned the river. Provided the trees were cleared, the mouth of Antietam Creek was within range. Up the Shenandoah River side, Key’s Ford was just out of range.
Clearly this was a sizable umbrella of protection for defenders of Harpers Ferry. Several dispatches within the Official Records mention “falling back under the guns of Maryland Heights” in the fall of 1863 and winter of 1864. I would contend it was this particular piece providing much of that coverage. I would further offer that this battery caused Confederate operations around Harpers Ferry to follow circuitous routes, avoiding the fall of shot and shell.