Fort Mulligan occupied a commanding height at the junction of roads leading north to New Creek, west to Beverly, Buckhannon, and Grafton, south to Franklin and Staunton, and east to Moorefield, Winchester, and Harrisonburg, making it a strategically important position during the Civil War. Tents filled the surrounding view during several periods of the war, including the spring of 1862, when nearly 20,000 Federal troops under Major General John C. Fremont camped in the nearby fields, and the winter of 1863-1864, when large numbers of troops were quartered here during the fort’s construction. Part of the infantry of Mulligan’s Irish Brigade made their winter quarters directly below this point. The fort’s outer works were built for great strength, with 10 to 15 feet of earth sufficient to stop the heaviest artillery shell and two feet enough to stop a rifle shot. A diary kept by Joshua Winters from September 3–7, 1863, records rain and clear weather, a Confederate attack on Stevens at Moorefield, a withdrawal and return to Petersburg, continued digging on the intrenchments, the arrival of the 54th and some cavalry, and routine picket duty.
