Bridge Placement at Edwards Ferry – Maryland Side

I took a bit of a break from Edwards Ferry and the Army of the Potomac’s crossing there in June 1863 (I’ve collected links to all those earlier posts on a separate page if you missed them).   Time to look at the site again, first looking at the ground itself, with the aim of estimating the location the engineers placed the bridges.   In my first post on Edwards Ferry, I offered this view of the site based on satellite imagery:

Google Earth Image of the Site Today

The modern subdivisions and road structure stands in sharp contrast to the depictions on wartime maps:

Section of McDowell Map showing Edwards Ferry

Based on research and visits to the site, I offer this rough sketch of the key points:

Key Points in the Edwards Ferry Vicinity

The blue areas are of course the waterways of the Potomac River, Chesapeake & Ohio (C&O) Canal and Goose Creek (with Cattail Branch forking off the later and running to the west).  A line roughly parallel to Goose Creek depicts the route of the Goose Creek Canal.  Blue-gray boxes show the locations of canal and river locks.  The green lines show the approximate routes of wartime roads.  Hashed lines on the north bank of Goose Creek indicate the higher ground on that side.  Finally the yellow boxes show the locations where I believe the bridges were laid.

I consider the locations of the canal locks particularly important to the bridge placement.  The engineers working on the pontoon bridges had to see these structures partly as “blocks” to work around.   Lock 25 of the C&O Canal sat almost directly opposite the mouth of Goose Creek.  While a wooden bridge spanned the canal at the lock, this was insufficient to support the movement of an entire army.  Indeed, on June 25, 1863 Captain Charles Turnbull noted, “…I will have two bridges over the river, one over Goose Creek at its mouth, and two over the canal”  (OR, Series I, Volume 27, Serial 45, p. 311).

Lock 25 Today

The modern park bridge is a simple structure supported by two steel beams.  In 1863, engineers may have laid simple wood plank bridges to span across the lock.  But keep in mind the steep berm on either side of the lock, and the hundreds of wagons and artillery pieces crossing in what must have seemed like an endless procession.  How long before the paths up and over the lock rutted out?  How long before the wooden spans wore out as they rubbed against the sandstone blocks?

I would offer a more easily maintained, and traffic-able, solution was a pair of single bay pontoon bridges – one above and one below the lock.  Such would match directly with the placement of the longer pontoon bridges across the river, straddling the mouth of Goose Creek, and give options for traffic control.  This also reserved the existing wooden bridge for the engineers’ use maintaining the pontoon bridges.

About two-tenths of a mile downstream of Lock 25 is the Goose Creek river lock.  Built in 1838, this two lock “staircase” lock allowed boats to pass from the C&O Canal across the Potomac to Goose Creek.  Designed to facilitate the flow of goods from Loudoun Valley, with the failure of the Goose Creek Canal, the river lock provided little more than easy access to the Potomac.

Goose Creek River Lock

The location of this river lock did not escape notice by senior officers in the Army of the Potomac.  On June 18, General G.K. Warren, while summarizing the Potomac River crossing points, noted that at Edwards Ferry, “…There is here an outlet lock from the canal into the river…” (OR, Series I, Volume 27, Serial 45, p. 149).  Going back to the dispatches between June 18 and 20, General Henry Slocum, commanding the 12th Corps then at Leesburg, considered a bridge at Edwards Ferry more a logistic arrangement rather than for movement into Maryland.   As such he wrote, “Our supplies should be sent from Georgetown, by canal, to Edwards Ferry.” (OR, Series I, Volume 27, Serial 45, p. 209).

The first pontoon bridge, built overnight on June 20-21, was placed well above the river lock, extending to the upstream side of the mouth of Goose Creek.  The Virginia side landing linked with Edwards Ferry Road, leading straight to Slocum’s forces around Leesburg.  I would further argue such placement ensured the bridge, and attendants working on the water, remained clear of the river lock, and also reserved the option to simply float canal boats to the Virginia shore for unloading.

Foot Bridge over Chanel to River Lock

For the second bridge, placed on the morning of June 25, the river lock offered the engineers the option to off load equipment outside the main canal, perhaps even directly into the Potomac.

But where were the Maryland side pontoon abutments in relation to the river lock?  No primary sources I’ve seen offer clarity in that regard.  From a common sense perspective, if the pontoon abutments were upstream from the river lock, engineers could pull barges and perhaps even pontoons, through the locks directly into the river without having to worry about boats breaking free and damaging the bridges.  When the Captain E.O. Beers, 15th New York Engineers, began construction of the lower bridge on the morning of June 25, the operation began on both shores.  I would argue the use of that river lock might allow the engineers to move heavy equipment to the Virginia shore without interfering with the 11th Corps then passing on the upper bridge.

The C&O River Lock Seen from the Virginia Shore

But again, no source tips the hand one way or the other in this regard.  What I would say is the river lock, and its “spur” channel, required the engineers avoid an abutment along a 200 yard section of river front – the landing had to be up or down stream of the lock, not on top of it.

C&O Canal in Vicinity of River Lock

Even with the main bridge abutments placed for that second bridge, the engineers faced the challenge of providing passage over the C&O and to the road toward Poolesville, Maryland.  A rise, perhaps only twenty feet in elevation, runs east of the canal, sandwiched between the Potomac and Cabin Run.  If I ever do locate a detailed first hand account, I would certainly wish to see some mention of the retaining walls (see photo above) along the canal south of Lock 25.

In short, it is my opinion that the bridge abutments on the Maryland side were placed above and below Lock 25 to allow for traffic flow.  I also believe in order to maximize the use of the river lock, the lower bridge touched the shore upstream of that canal spur.    But the key source I would offer to support that premise is the ground itself, along with consideration for the traffic flow.  If anyone can shed further light on the bridge placement, I am all ears!

Having covered the Maryland shore, in my next post I will look at the Virginia side.  Time and space permitting, I will discuss the interesting side notes about the Goose Creek Canal.

Published by Craig Swain

"Historical marker hunter" and Civil War enthusiast.

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