Notes on Monocacy Aqueduct, Clapham's Ferry, &tc.

Reference in C&O Canal Companion: Mile 42.2

Harper's Weekly depiction of the Aqueduct during the Civil War.


To be added

Mile 42.2 :

The aqueduct was designed by Benjamin Wright, sometimes referred to as "the father of American civil engineering." Initially, the canal company planned to use stone from "Mrs. Nelson?s quarry" at the base of Sugarloaf Mountain. According to the latest NPS research (in connection with the rehabilitation project), the stone proved to be too soft for its purpose, and Wright directed that the first three partially constructed piers be torn down. Instead, "white stone" from Joseph B. Johnson?s quarry, also referred to as granite, was ordered to be used for all structural purposes. Construction was beset with difficulties, as Wright left to work on other canal projects and the company passed the project through a succession of contractors. The aqueduct was finally completed under the direction of Alfred Crueger on April 1, 1933 and that section was watered in the last weeks of October 1933. (based on research
by Robert J. Kapsch of the National Park Service


On Lee's orders a second attempt to demolish the aqueduct was made by Brigadier General John Walker on the night of September 9. Lee's plan, as he described it to General Walker, was to isolate Washington, Baltimore, and Philadelphia from reinforcements from the west, starting with the canal and the B&O Railroad, and moving on to the destroy the Pennsylvania Railroad bridge over the Susquehanna. But Walker found the aqueduct so "admirably constructed" that there was no seam or crevice to insert a crowbar, and the drills that he had to make holes for the blasting powder were too dull and the rock too hard. As Union forces approached ...


In 1756, Josias Clapham obtained a license from the Virginia Assembly to run a ferry from his land in Virginia over to the mouth of the "Monocochisey" in Maryland. He was in direct competition with Noland's Ferry upstream, but the road to his crossing was less convenient. Perhaps for this reason, the Assembly set his rate at four pence, substantially lower than the sixpence charged by Noland. Clapham's rivalry with Noland appears to have petered out by the Revolutionary War, along with his ferry business. In 1816, a ferry was authorized here in the name of Hawlings, and by the time of the Civil War, the crossing-place at the Monocacy was known as Haulings or Hawlings Ford.


George Washington visited the mouth of the Monocacy, probably on October 17, 1790, after meeting with Georgetown property owners to discuss possible sites for the federal city. Francis Deakins owned land at the mouth of the Monocacy, and several weeks later sent Washington a rough plat of the area, half-heartedly adding, "Having no assistance in laying down the plats--much Other business on hand and a faint expectation of its possessing Superiour advantages to any other place, I hope will in Some degree apologize for the Roughness of it."

Deakins probably realized that prospects of placing the federal city above the falls of the Potomac were relatively unlikely (also see discussion of Washington's visit to Williamport, mile 99.6). However, there were no hard feelings -- Deakins' brother, William was a major property owner in the vicinity of Georgetown, and stood to gain from the placement of the capital at that location. When William Deakins died, Francis inherited his concerns (and sizable debts), and ended up head of the committee that welcomed President John Adams to the new capital in June of 1800.


Additional Notes

Monocacy Aqueduct Restoration Project:

As noted in the C&O Canal Companion, the Aqueduct has suffered a great deal of flood damage over the years, and is held together by unsightly steel braces. On Saturday, September 7, the National Park Service held a kickoff ceremony for the restoration of the Monocacy Aqueduct. The C&O Canal Association, the National Trust for Historic Preservation, and the American Society of Civil Engineers were given much of the credit for their efforts to get funding for the project. The C&O Canal Association raised more than $150,000 in contributions towards the restoration effort and the National Trust for Historic Preservation listed the Monocacy Aqueduct as one of 11 most endangered historic places in the United States, which led to a visit and show of support by First Lady Hilary Clinton in June 1998. Maryland Senators Sarbanes and Mikulski and Representatives Morella and Bartlett were also credited for their work in getting a $6 million federal appropriation for the project. The contractor on the project is Corman Construction, Inc., of Annapolis Junction, Maryland.

Aerial view of the juncture of the Monocacy with the Potomac
at the time of the 1996 flood; the aqueduct is partially
submerged in the foreground. (National Park Service)



General Walker's account of the attempt to destroy the Aqueduct:

Retracing our steps towards the Potomac, at ten P.M. of the 9th my division arrived at the aqueduct which conveys the waters of the Chesaepeake and Ohio Canal across the Monocacy. The attempted work of destruction began, but so admirably was the aqueduct constructed and cemented that it was found to be virtually a solid mass of granite. Not a seam or crevice could be discovered, in which to insert the point of a crow-bar; and the only resource was in blasting. But the drills furnished my engineer were too dull and the granite too hard; and after several hours of zealous but ineffectual effort, the attempt had to be abandoned. Dynamite had not then been invented, so we were foiled in our purpose, and about three o'clock A.M. of the 10th, went into bivouac about two miles and a half west of the Monocacy.



  • Benjamin Wright and the Design and Construction of the Monocacy Aqueduct, Robert J. Kapsch, excerpted from Canal History and Technology Proceedings, Volume XIX, March 18, 2000, (Easton, PA, National Canal Museum, 2000)
  • The Rehabilitation of the Monocacy Aqueduct of the Cheseapeake and Ohio Canal National Historical Park, Robert J. Kapsch, from International Conference on Preservation of the Engineering Heritage, Gdansk Outlook 2000, (Gdansk, Poland: Technical University of Gdansk, 1999)
  • See report of Major General Daniel H. Hill on attempt to destroy the aqueduct, September 4, 1862, Official Records, Series 1 - Volume 19 (Part I), page 1018.
  • "Harper's Ferry and Sharpsburg," by (General) John G. Walker, in The Century Magazine, May 1886. [Page images viewable on-line as a part of Cornell University's Making of America collection.]
  • The Papers of George Washington, Presidential Series, Volume 6, Edited by Dorothy Twohig and others, University Press of Virginia, Charlottesville, Virginia, 1996. [See discussion of Washington's trip up the Potomac in October 1790, pages 571-572, and Francis Deakins' letter to Washington dated November 12, 1790, on page 647. The editors note that the enclosed plat of the Monocacy area has not been found.]
  • Through a Fiery Trial, Building Washington, 1790-1800, Bob Arnebeck, Madison Books, Lanham, Maryland, 1991. [An extensive examination of the period of construction, based on letters, accounts, planning documents, and newspaper articles; also discusses Washington's choice of site and includes several references to William and Francis Deakins.]
  • The Potomac, Frederick Gutheim, originally published by Holt, Rinehart, and Wilson, 1949, paperback edition with new preface by the author published by The Johns Hopkins University Press, Baltimore, Maryland, 1986. [Contains a wealth of details about the region, evidently collected over many years; the opening chapter describes Francis Deakins as head of the welcoming party when President Adams arrived in Washington in June of 1790.]



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