To designate the Civil War Defenses of Washington National Historical Park comprised of certain National Park System lands, and by affiliation and cooperative agreements other historically significant resources, located in the District of Columbia, Virginia, and Maryland, that were part of the Civil War defenses of Washington and related to the Shenandoah Valley Campaign of 1864, to study ways in which the Civil War history of both the North and South can be assembled, arrayed, and conveyed for the benefit of the public, and for other purposes.