This marker commemorates the remains of the Centreville Confederate Military Railroad which is a Fairfax County Historical Site. I believe Fairfax County put it up themselves. This marker was put up because the railroad was built in the fall and early winter of 1861 for transporting supplies to the field armies to Generals Pierre G.T. Beauregard and Joseph Johnston and ran 6 miles from Manassas Junction, crossing Bull Run to Centreville Plateau. In 1861 the fall was unusually cold and rainy and turned the roads into unpassable mud traps and in order to supply the 40,000 troops in the winter quarters in Centreville General Johnston ordered the 6-mile railroad built to connect with the railroad lines in Manassas Junction. This marker was put up because it is the first railroad in the world built by the military for expressly military purposes. It was used to keep men and animals supplied and allowed the Confederate army to hold the position at Centreville Heights until they withdrew from the area in March 1862.