During the winter of 1863-1864, when a telegraph system ran along the Orange and Alexandria Railroad northwest of Stevensburg, signal stations on hills across Culpeper and Orange Counties were the best way for the Union and Confederate armies to pass messages. These stations often used tall scaffolds so flag signals could be seen over long distances with telescopes. The Union Signal Corps headquarters was on Mount Pony, called Pony Mountain by soldiers, with additional stations on Fleetwood Hill, Cole's Hill, Cedar Mountain, and Culpeper Courthouse. Mount Pony had first been held by the Confederates in 1862 and later in the 1863 Battle of Brandy Station, but by the winter of 1863-1864 the Union used it as the central relay station, within view of army headquarters to the north and stations overlooking Confederate positions to the south, while Confederate forces used Clark Mountain as their central station during the winter encampment. On clear days, rotating Confederate guards could easily be seen from Union-held stations watching each ford across the Rapidan River, and conversations between signalers discussed troop movements and other useful intelligence. Unlike the telegraph lines, the Union Signal Corps was staffed entirely by military personnel and was led by Captain Lemuel North, Chief Signal Officer. On February 24, 1864, a signal exchange between Mount Pony and Army of the Potomac headquarters near Fleetwood Hill reported a brigade of infantry moving toward Morton's Ford, identified as pickets from Clark Mountain, and confirmed at 11 a.m. that they were Confederate.
