For more than a half mile along this footpath stands a section of Civil War era earthworks. Over five miles of earthworks were constructed as defensive lines near Centreville, Virginia, in late 1861 as part of a larger defensive system that extended 17 miles from Centreville to Union Mills, to Occoquan and Dumfries. Much of the earthworks have been lost to development. In the 1980's, a conservation easement to preserve this heritage was established along Union Mill Road.