The Ball’s Bluff Battlefield Historic District and National Cemetery is located along a sweeping curve of the Potomac River within Loudoun County, Virginia and Montgomery County, Maryland.  Ball’s Bluff Battlefield is nationally significant for its association with the early stages of the Civil War as one of four consecutive unsettling Union defeats in both the Eastern and Western Theatres that led to the creation of the Congressionally appointed Joint Committee on the Conduct of the War. The actions of the Joint Committee had far-reaching implications for the operations of the military throughout the remainder of the war. The Ball’s Bluff Battlefield is composed of two tracts: a primary parcel of over 3,000 acres that straddles the Potomac River; and a 10-acre parcel that encompasses the Civil War-era earthwork known as Fort Evans. The battlefield is composed of terrain, either wooded or cleared, that has changed very little in terms of its essential character since 1861. This National Historic Landmark nomination update includes a large boundary expansion, and a revised understanding of the Battle of Ball’s Bluff from additional scholarship and study since the listing of the original 76-acre Battle of Ball’s Bluff and Ball’s Bluff National Cemetery.  In addition to the original Ball’s Bluff Battlefield, the portions of this expanded district in Virginia is located within the Catoctin Rural Historic District and was listed under the The Civil War in Virginia, 1861 – 1865: Historic and Archaeological Resources MPD.