William J. L. Nicodemus


William J.L. Nicodemus, The Signal Corps in the War of the Rebellion, p.160



William Joseph Leonard Nicodemus (1834-1879) was born near Hagerstown, Maryland, and graduated from West Point in 1858.

Before the Civil war, Nicodemus served in the Southwest with Albert J. Myer––future founder of the Signal Corps––developing “aerial telegraphy”. Nicodemus was instructed in Myer’s signal methods.

For gallant and meritorious services at the Battle of Valverde, New Mexico, in February 1862, Nicodemus was given a brevet promotion to major.

In 1863, Nicodemus assumed command of the Signal Camp of Instruction, on Red Hill, Georgetown, D.C. In charge of communications between Harper’s Ferry and Washington, Nicodemus saw action during Gettysburg campaign.

November 10, 1863, Albert Myer relieved of the command of the Signal Corps by the Secretary of War; Maj. Nicodemus appointed in Myer’s place.

In late 1864, Lt. Col. Nicodemus published an annual report critical of the Secretary of War––specifically, Stanton’s transfer of field telegraph trains from the Signal Corps to Stanton’s military telegraph department. The report also referred to the fact that enemy signal messages were being read (which the enemy knew).

Stanton ordered all copies of the report to be destroyed. For “aid and comfort to the enemy”, Nicodemus was stripped of his commission and dismissed from the service. He was succeeded as acting chief signal officer by Lt. Col. Benjamin F. Fisher. (Nicodemus was reappointed as Lieutenant Colonel, Signal Corps, March 31, 1865.)




William Nicodemus married Frances E. Pettit of Georgetown, Holy Trinity Church, December 27, 1864 ( one day after his dismissal from the Army).


For $1800, Trustees of the Congregation of the Presbyterian Church sell to William J. L, Nicodemus and Fanny E. Nicodemus, his wife, lot 7 in The Slip, on West (P) Street, Georgetown. (DC Liber NCT59 (1865) ff.7, 9)

Richard Pettit and wife Mary Ann sell to William J. L, Nicodemus, USA, lots 89 and 90, Beatty and Hawkins’ Addition To Georgetown (Wisconsin Avenue and Prospect Street?) (DC Liber ECE19 (1867) f.307)


At the end of the war William Nicodemus was restored to his regiment, the 12th Infantry, as Captain, and stationed in New York, Richmond, Petersburg, and Fredricksburg, and Washington, D.C. In 1870, he was honorably discharged from the United States Army at his own request.

“After the war, when Confederate archives were reviewed, it would come to light that a Baltimore resident had written Jefferson Davis in March of 1861, to the effect that Nicodemus desired a commission in the Confederacy. Because of this letter, the War Department would later refuse to assign Nicodemus to a regiment and he would request and receive a discharge, perhaps never knowing where the trouble lay.”

(Mark C. Hageman, The Origin of Union Signal Communications)


William Nicodemus, professor of civil and mechanical engineering at the University of Wisconsin, died January 6, 1879.





J. Willard Brown, The Signal Corps in the War of the Rebellion, 1896, pp.36-37, 160,842)

Mark C. Hageman, The Origin of Union Signal Communications, Signal Corps Association, 1860-1865





 Carlton Fletcher

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