McLean in Fairfax County, Virginia — The American South (Mid-Atlantic)

Auxiliary Battery

Fort Marcy, Virginia

Photographed by Craig Swain, August 24, 2007

1. Auxiliary Battery Marker

Inscription. An extensive line of rifle trenches connected the advance works of Fort Ethan Allen and Fort Marcy and extended to the west bank of the Potomac River. Auxiliary batteries for the field guns, strategically placed, provided additional strength to afford a full view of the fort.

Topics and series. This historical marker is listed in these topic lists: Forts and Castles • War, US Civil. In addition, it is included in the Defenses of Washington series list.

Location. 38° 56.086′ N, 77° 7.558′ W. Marker has been damaged. Marker is in McLean, Virginia, in Fairfax County. It can be reached from George Washington Parkway, on the right when traveling west. Located inside the Fort Marcy Park, at the western edge of the interior of the fort. The park is best reached from west bound George Washington Parkway, with no exits from the east bound lanes. Touch for map. Marker is at or near this postal address: 639 Chain Bridge Rd, Mc Lean VA 22101, United States of America. Touch for directions.

Regionally, this marker is in the Washington Metropolitan Area

and in Northern Virginia.

It is also in the American South,

specifically in the Upper South,

and in the Mid-Atlantic.

Globally, it is in the North Atlantic Region,

North America,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once the territory of the Mississippian Culture,

one of the original Thirteen Colonies,

one of the Confederate States of America,

and the Antebellum South.

Other nearby markers. At least 8 other markers are within walking distance of this location: Fort Marcy (within shouting distance of this marker); Fort Marcy, Virginia (about 300 feet away, measured in a direct line); Inlet Locks (approx. 0.4 miles away in Maryland); Pimmit Run and Chain Bridge

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(approx. 0.6 miles away); The Mouth of Pimmit Run (approx. 0.6 miles away); Original Federal Boundary Stone, District of Columbia, Northwest 4 (approx. 0.6 miles away in Maryland); Chain Bridge (approx. 0.6 miles away); Clay and Randolph Duel (approx. 0.7 miles away). Touch for a list and map of all markers in McLean.

Another marker is no longer nearby. Arlington County / Fairfax County (was approx. ¼ mile away but has been confirmed missing).

More about this marker. An engineering diagram of the fort showing portions of the exterior works and auxiliary batteries is on the right side of the marker.

Auxiliary Battery Marker Stands at the West Edge of the Fort Proper image. Click for full size.

Photographed by Craig Swain, August 24, 2007

2. Auxiliary Battery Marker Stands at the West Edge of the Fort Proper

Portions of the Exterior Works image. Click for full size.

Photographed by Craig Swain, August 24, 2007

3. Portions of the Exterior Works

These parallel the front of the fort itself, and would have been used by supporting infantry.

Map of Fort Marcy and Its Auxiliary Batteries image. Click for full size.

National Archives

4. Map of Fort Marcy and Its Auxiliary Batteries

Detail from Contour Map of the Sites of Fort Ethan Allen, Fort Marcy, and Batteries in their Vicinity, NAID: 122207858, Drawer 171, 210L, Maps and Charts.

Photographed by Evan Dwyer, January 17, 2026

5. Auxiliary Battery Marker

Marker is heavily worn and damaged.

Credits. This page was last revised on March 12, 2026. It was originally submitted on October 21, 2007, by Craig Swain of Leesburg, Virginia. This page has been viewed 2,009 times since then and 25 times this year. Last updated on March 12, 2026, by Evan Dwyer of Richmond, Virginia. Photos: 1, 2, 3. submitted on October 21, 2007, by Craig Swain of Leesburg, Virginia. 4. submitted on March 13, 2024, by Allen C. Browne of Silver Spring, Maryland. 5. submitted on March 12, 2026, by Evan Dwyer of Richmond, Virginia. • Bernard Fisher was the editor who published this page.