Friday, November 9, 2012

The Chain Bridge Defenses: A Mysterious Blockhouse

Following a recent trip to the Falls Church Library, I decided to swing by my local Books-A-Million on the way home.  As I was browsing the bargain bin, a Blue & Gray Press reprint of Volume 5 of Francis T. Miller's famous, The Photographic History of The Civil War, caught my eye.  This volume focuses on forts and artillery and includes a chapter on "Defending the National Capital."  A photograph on page 75 entitled, "Blockhouse at the Chain Bridge, Above Georgetown," really peaked my curiosity.  I've read a lot about the Chain Bridge and the Civil War defenses of Washington, but had never come across any mention of a blockhouse being built at the bridgehead.  I was determined to learn more about the subject of this unique photograph. 

Photograph and caption from p. 75 of Miller's The Photographic History of The Civil War, Volume 5: Forts and Artillery (courtesy of Perseus Digital Library, Tufts University)
The caption for the photograph in Miller's Photographic History includes no indication of when it was taken or who took it.  The image depicts a small group of persons gathered at the end of the Chain Bridge below the blockhouse.  At least one woman is standing there, along with a few children.  Given the format of digital reproduction that I found, it is difficult to magnify the photograph on a computer to see more detail. 

Virginia Side or D.C. Side?

During the Civil War, the D.C. side of the Chain Bridge crossed low over the Chesapeake & Ohio Canal before meeting the shore (see photograph below), while the Virginia side passed high over the Potomac River and ended abruptly at a steep bank.  (Barnard 80.)  The bridge in Miller's book appears to hit the shore at the river, or Virginia, end.  A modern photograph of the same location, which has not changed much since the war, supports this conclusion (see below). 

A wartime view of the Georgetown/D.C. end of the Chain Bridge (courtesy of Library of Congress).  Note the Chesapeake & Ohio Canal immediately below the bridge.

Contemporary view of the Chain Bridge and the Potomac at the Virginia shoreline, looking south (courtesy of Wikipedia).  The curve in the river and the shape of the palisades on the Virginia side appear to match the same features in the photograph from Miller's Photographic History.
At the time of the war, the ruins of an industrial brick building (or buildings) stood on the south side of the Virginia end of the bridge.  A lone chimney also rose above the Chain Bridge around the same area (see the series of photographs below).  Both of these features appear to be missing from the photograph in Miller's classic work.  The ruins were likely situated farther down the road, outside the frame of the photograph.  At some point when I have more time I'd like to hike around the site to get a better idea of where the blockhouse and ruins were possibly located in relation to the old bridge.

Ruins of an old manufacturing building on the Virginia side of the Chain Bridge (courtesy of Library of Congress).

Another view of ruins near the head of the bridge on the Virginia side (courtesy of Wikipedia).

View from heights above the bridge, showing the ruins of a brick chimney (courtesy of Library of Congress).  The remnants of the brick industrial building are visible below, to the right of the Chain Bridge.
A Blockhouse?

During the war, the Chain Bridge was one of three strategic crossings of the Potomac River near Washington.  As Gen. John G. Barnard, Chief Engineer for the Department of Washington, recalled, "The possession of the Chain Bridge communication with the opposite shore of the Potomac, incidentally important in a defensive point of view, was essential to our operations in Virginia and to the prestige of our arms."  (Barnard 47.)  Accordingly, the Union Army constructed several works on both sides of the Potomac to protect this vital link between Washington and Virginia.  In the Old Dominion, Forts Marcy and Ethan Allen, along with a system of rifle trenches and batteries, served as the main defensive works.  On the D.C. side, a battery of field guns sat at the end of the bridge; Battery Martin Scott occupied the heights above.  Batteries Vermont, Kemble, Parrott, and Cameron also swept the land around Chain Bridge in Virginia from their dominant positions on the other side of the river.*

The Union Army constructed several blockhouses around the nation's capital, but commonly-consulted sources on the defenses of Washington do not list a blockhouse as part of the works at the Chain Bridge.  Three blockhouses were erected on the Virginia side of the Aqueduct Bridge (near today's Key Bridge).  Blockhouses were also built near Alexandria at Hunting Creek and on the Leesburg-Alexandria Turnpike around Ft. Ward.  In November 1864, the Union Army began to erect a series of picket posts, including blockhouses, that stretched from Prospect Hill on the Leesburg-Georgetown Turnpike (a few miles from the Chain Bridge) to Vienna, Fairfax Courthouse, and Fairfax Station.  

A wartime report on Washington's defenses offers a clue as to the construction of a blockhouse at the Chain Bridge.  On October 25, 1862, Secretary of War Edwin M. Stanton appointed a Commission to examine the adequacy of Washington's defenses.  Barnard served on the Commission along with other military experts, including Quartermaster General Montgomery Meigs and the Chief of Engineers, Gen. John G. Totten.  In December 1862, the Commission offered its recommendations.  After reviewing the state of the defenses around the Chain Bridge, the Commission concluded:
[S]ome defensive arrangements are necessary immediately about the head of the bridge; probably two or three small works, or, perhaps, block-houses would suffice.  (OR, 1:21, 909.)
Several months later, on May 22, 1863, Barnard complained to the head of the Department of Washington, Gen. Samuel P. Heintzelman, that he was running low on funds to hire workers for the improvements recommended by the Commission.  As to the Chain Bridge, he explained:
. . . there remains much to be done, and I will continue a force of mechanics, with some laborers, provided I can have the assistance of the troops.  (OR, 1:25:2, 513.)
However, a few weeks later, on July 7, 1863, Barnard reported to Col. J.C. Kelton, the Assistant Adjutant-General:
The work has been prosecuted with all the vigor the means at my disposal would admit. Although the winter season was most unfavorable for such work, and with the limited amount of money available, as well as with regard to economy, it was not deemed advisable to employ very large gangs of hired laborers, yet, by aid of the troops, working whenever the weather and state of the ground would permit, the most essential works recommended by the commission, such as . . . the additional works at the Chain Bridge. . . were all pressed forward, so as to be in a condition, if not complete, at least of efficiency, for their uses, with the return of the season, when active field operations might throw Washington upon its defenses.  (OR, 1:27:3, 596.)
Barnard's correspondence indicates that despite resource constraints, the Union Army completed or made substantial progress on the recommended works at the Chain Bridge -- which possibly included one or more blockhouses -- by mid-summer of 1863.  However, in his post-war report on the defenses of Washington Barnard elaborated on the fate of the blockhouses at the Chain Bridge:
It has been seen that the Commission recommended that some defensive arrangements should be made immediately about the head of the bridge, suggesting two or three small works or block-houses.  This recommendation, though always contemplated, was never complied with. Doubtless, however, this interior and limited inclosure of the bridge-head is a necessary and important part of all extensive "tetes de pont." (Barnard 47.)
So, is Barnard wrong about the blockhouse?  After all, pictures presumably don't lie.  His report was published several years after the close of the war, and his memory may have grown a bit cloudy, particularly if the blockhouse was built following his departure from the Department of Washington in 1864.  Alternatively, the U.S. Army may have constructed the blockhouse at some point during the post-war period, and Miller's Photographic History may have erroneously classified the image as a Civil War-era one.  If that is the case, then for what defensive purposes was the blockhouse built?  After all, an active rebellion no longer threatened the river crossing at the Chain Bridge.  Another possibility is that Miller's book misidentified the photograph, and that it actually depicts another bridge and another blockhouse somewhere else that bears an uncanny resemblance to the area around the Chain Bridge.  Whatever the theory, one thing is certain -- the complete story behind the "blockhouse at the Chain Bridge" remains a mystery.


*A sub-caption to the photograph in Miller's Photographic History explains that "[the Chain Bridge] approach was defended by Forts Ethan Allen and Marcy on the Virginia side, and by Batteries Martin Scott, Vermont, and Kemble on the Maryland side of the Potomac."  (Miller, Vol. 5, 75.)


Aside from the Official Records, the following sources were useful in compiling this post:

John G. Barnard, A Report on the Defenses of Washington (1871); Benjamin Franklin Cooling III & Walton H. Owen II, Mr. Lincoln's Forts: A Guide to the Civil War Defenses of Washington (2010 ed.); Historical Marker Database, "Pimmit Run and Chain Bridge"; Francis T. Miller & E.O. Hunt (eds.), The Photographic History of the Civil War in Ten Volumes, Volume 5: Forts and Artillery (1911); National Park Service, A Historic Resources Study: The Civil War Defenses of Washington, Parts I & II (2004).


Greg Taylor said...

A fascinating mystery indeed. It always amazes me how much of recorded history is comprised of erroneous or conflicting information. It may be a minor issue in the scheme of things, but yet the record deserves to be set straight. Thank you for delving into this "issue." I will be interested to see what is revealed.

Ron Baumgarten said...

Thanks, Greg. Glad you enjoyed the post. I too am always amazed at how a simple story is never that simple after all. I am one of those detail-obsessed people--perhaps that's why I became a lawyer--so it's hard for me to overlook even the most minor of discrepancies. I just couldn't take that photo at face value given what I had read and written about the Chain Bridge defenses. Hopefully some day I will come across more information, or a reader will send something my way!

Chuck Siegel said...

The photograph with the Block House is misidentified in Miller. The actual site is the Orange and Alexandria Railroad Bridge over Bull Run. The abutment in the photograph still remains standing. The site of the Block House is now overgrown, but at one time you could make out the depression of the footprint.

Ron Baumgarten said...

Chuck--I think you have helped to solve the "mystery" behind this photograph! What other evidence have you found to back up the proper identification? I notice that your site has a listing for the Bull Run Bridge, and indeed, the engraving and the photo of the abutment seem to support your theory. Is there anything else you've come across? (By the way, I really like your website on the O&A R.R.)

Chuck said...

Thanks for visiting my web page.

There are several other photographs taken of the bridge and the block house as well as a drawing of the block house. All identified as the Bull Run Bridge. If you visit the bridge site you can match up some of the stones in the photo with the abutment and the hill where the block house stood is still prominently overlooking the current RR bridge. There is no doubt that the site is the Bull Run RR Bridge.

chuck said...


Here is another view of the bridge and block house located in the Library of Congress:

Ron Baumgarten said...

Thanks, Chuck. After getting your comment yesterday, I did an image search, including the LOC database of Civil War photographs. The Miller image looks an awful lot like the site at the Bull Run R.R. Bridge! (In fact, in my daily drives across the Chain Bridge, I was having a really hard time placing where that blockhouse was in relation to the topography at the spot! Now I know why....) Have you actually seen the original photograph from Miller's at the LOC or elsewhere? I am interested if it is marked with a description and date of any sort. How did Miller's get it wrong? At some point within the next few weeks, I'd like to do a separate post to update readers on what you've alerted me to. If you don't mind, please email me at so we can have a more detailed dialogue very email. Thanks, again!

Keith Yoder said...

Hi Ron - enjoyed your article as always. You can see some more recent photos of the area of the abutment and blockhouse on HMdb.

Ron Baumgarten said...

Thanks, Keith. These are helpful links, and glad you enjoyed the article. Incidentally, I went to a lecture tonight at the McLean Historical Society on the history of the Chain Bridge. The author of a new book on the bridge, Carole Herrick, believes that the picture is indeed the Chain Bridge. It looks like we have a few competing interpretive schools of thought!

Debbie Robison said...


Keith sent me a link to your site, which I have enjoyed reading. Keith noticed a similarity between the photo in this blog and a photo on the cover of the book Stone Ground .

The photos are available online at

Search for the following numbers:

I agree that this is Bull Run bridge.

Ron Baumgarten said...

Thanks, Debbie. I am glad you have enjoyed the site. These links are extremely useful, particularly because you can enlarge the photographs. It seems that the image from Miller in my post, which is one of the photos you identified on the Archives site, actually has railroad tracks across it. I also saw the wheel from a railcar at the bottom of the bridge near the abutment. Undoubtedly, Chain Bridge was not a railroad bridge! It does appear, however, that the title of the photograph does not name the Bull Run R.R. Bridge, so it seems Miller tried to identify the location and mistook the picture for Chain Bridge.