On Monday, September 15th, a day after the Battle of South Mountain, the last remaining barrier between the Confederate army and the Union army was now under Federal occupation. With the layout of South Mountain, and a clear view of the Cumberland Valley below, it wasn’t long before detachments of the Union army began establishing communication and observation posts.
According to the official records, during the day of September 15th, 1862, orders came from the commanders for the establishments of several posts located along the mountain ridges of South Mountain. Two lieutenants by the name of Camp and Clark took position on the crest of South Mountain to communicate with General George McClellan’s headquarters. Lieutenants Edward Halsted and Edwin Pierce took position on the mountain near the main road, but were withdrawn during the day.
At 2:00 am on September 16th orders were sent to Captain Benjamin Fisher, who was at Boonsboro, to bring the party forward as rapidly as practicable to near the Antietam Creek. Captain Fisher was also directed to establish an officer at the Washington Monument observation post, so he ordered Lieutenant Halsted to report there, on Monument Knob. Lieutenant Halsted, as well as all members of the signal corps located on South Mountain and Elk Ridge were to report any movements of the Confederate army visible at any point in the Cumberland Valley, whether it was dust or smoke.
By 10:00 am the Washington Monument station was communicating with the other established stations as the main Union army approached Antietam. Lieutenant Halsted was instructed to communicate any movements by the Confederate army during the battle. Careful telescopic examinations were made of the valley. One observation from Washington Monument, as well as one at Elk Ridge, reported that the Confederate army was at Sharpsburg.
As the Union army prepared to meet General Robert E. Lee’s Confederate army at Sharpsburg, the officers at Washington Monument were ordered to be at their post both day and night. The Washington Monument station was worked with peculiar labor. I am unsure if this happened or not, but at some of the other signal stations it was necessary to observe, at times, from the top of a tree while the signals were made from a point beneath, among the branches, where the flagman could only sustain himself by exertion.
During the Battle of Antietam, reports that the Washington Monument signal station failed to report to the signal station near Hagerstown was recorded. Afterward, an investigation was launched against those officers at Washington Monument, as they were given direct orders to be on alert. In Albert Myers’ report, he stated; “The case of an officer absent from his station is now under investigation. I have only to regret that the efforts of those who well did their duty were not followed by successes to our arms, to which they could claim to have contributed.” On September 18th, those stations were held in the same positions for observation. The station communicating with Washington Monument, which had been withdrawn during the 17th, was reoccupied.
A month later during General J.E.B. Stuart’s Raid in Pennsylvania on October 9th-12th, Union signal corpsmen under the command of Captain Benjamin F. Fisher were ordered to reopen Washington Monument for observation by Major Albert Myers on October 11th. Captain Fisher communicated with Lieutenant Spencer who was stationed at Hagerstown, and was also ordered to communicate with those stations located on the Catoctin Mountain. Stuart’s cavalry never back-tracked toward Hagerstown or Williamsport. Instead Stuart made his way toward Cashtown, turning south to Fairfield, before crossing the Mason and Dixon Line at Emmitsburg and then crossing the Potomac River near Hyattstown. Because of this, the Washington Monument signal station was ordered to cease.
The photo is from the LOC and is of Elk Ridge during the Battle of Antietam