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The Keystone Battery of Pennsylvania

Battery "A", 1st Regiment Light Artillery (43rd Volunteers)

U.S. Military Telegraph

Compiled by Kevin Saville

By 1861 when the American Civil War broke out, the Morse electromagnetic telegraph system was well established as the first reliable means of electric communication in America and Europe.  Samuel Morse and Alfred Vail had first demonstrated effective instruments and Morse code in 1844; railroads began to use the telegraph to control traffic in 1851.  Western Union was organized in 1856 with lines connecting the U.S. from the eastern seaboard to the Mississippi.  In July, 1861, work on the first transcontinental line to San Francisco via Salt Lake City was begun.  By January, 1862, it was completed and instant communication across the continent was possible.  In 1864, the first telegraph line was extended north from San Francisco to Olympia on September 8, 1864; to Seattle on October 26, 1864; and to New Westminster, British Columbia, on March 21, 1865.  The first transatlantic cable was laid in 1858 but a transatlantic cable was not continuously successful until after the Civil War in July, 1866.

The telegraph required operators who could read a digital, or on-off, signal in Morse Code.  Although this signal was originally captured on paper tape, it was soon found that reading the Morse instruments' "click" and "clack" by ear was much faster and easier.  With experience, operators were able to read entire words by listening to the string of "dots" and "dashes" that comprised each letter and word.  Proficient operators routinely sent and received messages during the Civil War, using a "straight" key, at 20-22 words per minute.

In order to avoid the likelihood of intervention, both sides used ciphers to conceal the true meaning of their communications. Over ten different ciphers were effectively used by Union operators during the war to thwart Confederate espionage.  Messages written in Union cipher resulted in important words for people and places being substituted with unrelated words according to closely controlled cipher books, and words in sentences being reordered using a word matrix.  Confederates typically used the simpler Vigenere cipher for polyalphabetic substitution and employed a cipher disk, or paper reel, to define the substitutions.  Their messages were far from secret and the Union regularly cracked their messages.  Confederates relied on three key phrases: "Manchester Bluff", "Complete Victory", and as the war came to a close, "Come Retribution".

In 1860, Congress authorized the formation of the U.S. Army Signal Corps, headed by the former army surgeon Albert J. Myer, who had developed an effective aerial signaling system.  Myer was also a former Morse telegrapher and wanted to have control of the electric telegraph system during the war.  In spite of Myer's ambitions, the U.S. Military Telegraph was formed in 1861, composed of civilian railroad telegraphers using the Morse system.  For the Signal Corps, Myer chose to use an English Bain telegraph system with needle pointers and then the Beardslee magneto-electric telegraph system because proficiency with Morse code was not needed to operate them.  However, in 1863 at Chancellorsville, poor conditions resulted in the Beardslee telegraph transmitting garbled messages.  As a result of that situation and clashes with Secretary of War Stanton, Stanton ordered the Signal Corps to relinquish all electric telegraph operations to the U. S. Military Telegraph.

In The Telegraph, Lewis Coe wrote, "The members of the U.S.M.T. emerged as the unsung heroes of the war.  Serving in the field alongside the soldiers, they were exposed to all the hazards of combat, yet they could not claim any of the benefits normally due a member of the armed forces.  If captured, the civilian operators ran the risk of being shot as spies.  Their services were applauded but after the war largely forgotten by the government they had so faithfully served.  As civilians without military rank, they usually wore civilian clothes.  However, in some areas, an "undress" uniform was authorized, consisting of dark blue blouse and trousers; buff, white, or blue vest; and forage cap.  In such a uniform, they caused confusion as to what, if any, rank they held.  In 1862, U.S.M.T. operators were paid $40 to $60 per month.  By the end of the war, their pay ranged from $75 to $150 per month - or $3 to $6 per day if they worked six days per week.  This was pretty good income for that time."

Both Union and Confederate commanders utilized information obtained from experienced telegraph scouts who tapped the lines of the enemy.  One of the south's most skillful operators was George Ellsworth who accompanied numerous rebel forces on raids deep in northern territory.  From the electric telegraph, Ellsworth was able to determine the location and strength of Union forces and send false messages to create anxiety and confusion.

During the war, the U. S. Military Telegraph utilized existing telegraph lines along the railroads and strung temporary lines, as needed, to the battle fronts.  Between May 1, 1861 and June 30, 1866, 15,389 miles of lines were constructed by the U. S. M. T.  Approximately one thousand of those miles were temporary field lines.  Permanent lines were composed of heavy, uninsulated, uncoated or galvanized, iron or steel wire suspended by glass, white flint, or bone rubber insulators fastened to substantial wooden poles.  Temporary lines were erected by U. S. M. T. linemen attached to "flying telegraph" wagon trains.   Metal lances fifteen feet long were stuck in the ground and a hood at their upper point held up insulated, stranded copper wire.  Permanent stations and battery wagons contained a full complement of instruments: sending key, main line relay, and sounder.  Field stations, linemen, and telegraph scouts often utilized the pocket relay which was a versatile, boxed instrument with sensitive, quiet relay and small brass strap sending key.

Galvanic current for all telegraph circuits was supplied by either Grove or Daniell cells.  Each Grove cell produced nearly two volts whereas a Daniell cell produced one to 1.5 volts.  Although the Grove cell was more powerful, it required an expensive platinum electrode (along with one composed of zinc) and dangerous nitric acid and sulfuric acid.  In contrast, the Daniell cell required inexpensive copper and zinc electrodes and relatively safe copper and zinc sulfate for the electrolytes.  Battery wagons during the Civil War typically carried 100 Daniell cells which produced slightly over 100 volts of direct current.  However, at that time telegraphers did not pay attention to electromotive force, or voltage; they simply wanted enough current to flow to activate the electromagnets on their relays and sounders.  This current was typically 20-60 milliamperes on earth ground-return circuits that activated higher resistance (150 ohm) relays and 80 to 120 milliamperes on local circuits that activated low resistance (4-8 ohm) sounders.

The Morse code was comprised of short and long circuit closures which made the sounder "click" when activated and "clack" when deactivated.  The difference in time duration between a "click" and a "clack" defined whether it represented a "dot" or a "dash".  A "dash" was usually about three times longer than a "dot" but there were exceptions, as indicated below (other expressions in parenthesis).

A: click-clack click...clack (.-)
B: click...clack click-clack click-clack click-clack (-...)
C: click-clack (.. .)

Morse Code is shown to the left, below, from an 1860's source, with spacing representing the timing between short (dot) and long (dash) elements.

Internet Sources for Civil War Era Telegraphy

Telegraph instruments during the Civil War,

Tom Perera's link page,

Morse Telegraph Club's Internet Links page,

Morse Telegraph Club's website,

Morse Interface Software and Circuits by Les Kerr (a Bellevue resident, good friend, and retired software engineer),

History of the U.S. Military Telegraph and U.S. Army Signal Corps,

Wikipedia entry for electric telegraph,

Telegraph living history,

Telegraph living history,

Civil War Events in Washington State (including major reenactments where there will be a telegraph depiction),

About Kevin Saville

Kevin Saville is president of the Seattle-Tacoma chapter of the International Telegraph Club and is secretary of the Washington Civil War Association.

His email address is