File:New defenses erected at Centreville, Virginia LOC gvhs01.vhs00257.jpg

English: Originally built by the Confederates and used for winter quarters in 1861-1862, the defenses around Centreville were also used by the Union Army to cover the retreat back to Washington after both 1st and 2nd Bull Run. When Lee began concentrating his forces around Culpeper in July 1863, and Meade, not to be outdone, moved his army to a position opposite them along the Rapphannock River, the stage was set for what appeared to be a 3rd Bull Run. However, the back and forth movements of both armies that took place through the summer and into the fall culminated in the Bristoe Campaign, 9 October-9 November. Each time the Army of the Potomac crossed to the south side of the Rappahannock, or re-crossed in retreat, the Engineer Brigade was called to construct the necessary bridges. In between assignments, the brigade returned to camp at Centreville. Shows a series of forts and redoubts built primarily to the east of Centreville, in Fairfax County, Va., and the use of slashed trees and barricades as defenses.