Prior to the Civil War, an assistant surgeon Albert J Myer, while stationed in Texas, observed Indians signaling with their lances. Meyer believed military units could send signals over long distances by using a single flag and devised a system using simple codes and lightweight materials.  This system of using flags, which became know as the "wig wag" system, a type of arerial telegraphy was used by both armies during the civil war.

Myer, using 1's and 2's, in various combinations, produced an alphabet by a flag wave to the left (1) or right (2) and a dip to the front was a number 3,
       Albert J Myer
The number 3 had a specific meaning as to the combination of 1's and 2's as shown below:

3= end of word
33= end of sentence
333= end of message

In 1860, Major Meyer got a chance to test his new method of signaling in New Mexico during the Navaho campaign..  After the outbreak of the Rebellion, Federal Officers still refused to accept this new concept until the Confederate Signal Corps proved so effective at the first Battle of Bull Run.

E. Porter Alexander had studied under Myer along with J.E.B. Stuart, practiced this new system of signals at the Narrows in lower New York before the outbreak of the war and Capt Alexander was the Confederate Chief of Signals at the Battle of Bull Run.

The Confederate Signal Corps was formed April 1862 and the Federal Signal was established March 1863.

A Signal Party was equipped with a signal kit that consisted of seven flags of different colors and sizes along with devises used for signaling at night.
(see equipment)

The Signal Party was made up of three men:

An Officer (US) or Party Chief (CS) had complete command of the signal party and was the only one authorized to send or accept messages from other stations.

A scribe who's duty was to record all incoming and outgoing messages along with the time in the commander's signal book or in a book that he possessed. The scribe must also assist the flagman in all duties and take over as flagman if necessary.

The flagman stands in perfect view and directly in front of the station.  When sending a message he must flag with speed and assertion and do so  accurately so that the contact station can read and understand the message sent.  When recieveing, it is the flagman's duty to call out the attention to the signal station and read aloud the message being sent to the officer and scribe.  He will also call out any error made by the contact station.

The Signal Corps had a difficult slow go of being recognized as a Corp because of their secrecy and being a new corp.  A lot of soldiers didn't understand the purpose of the Signal Corps and why the flags always seemed to be moving or what the flags waving meant.  But slowly they began to understand the significance of the Signal Corps and the invaluable aid they gave the Army.
E Porter Alexander
Signal Corps officers lowering flag at their camp near Georgetown, General Albert J Myer, in civilian dress, at right of pole.            Library of Congress
Origin of the Signal Corps
Signal Stations During The Civil War
                  Then and Now
Then:  Located on South Mountain, this monument was used by Federal signalmen during the battle of Antietam, 1862.

Now: Rebuilt by the citizens of Boonsboro.  On July 4, 1827, this was to be the first monument to be constructed to honor George Washington.
Washington Monument Signal Station
Then:  Union signal station at Elk Ridge overlooking the Antietam Battlefield.  Library of Congress Photo

Now:  Photo taken from Antietam facing Elk Ridge.
Area photographed is where signal station may have been located.
Elk Ridge Signal Station
Little Round Top
Then:  During the battle of Gettysburg in 1863, of the many signal stations located throughout the battlefield, Little Round Top is probably the most mentioned station today

Now:  At Little Round Top there is a plaque dedicated to the Union signalmen that held that station during the Battle of Gettysburg.
Return Home
Remains of Stone Fort, Harpers Ferry
Then:  A signal station was established at the Tibbs house for a brief time
on April 9th.  Lt Frederick Amsden was Chief Signal Officer during this time.
(photo taken from the front porch of the McLean house)

Now:  Evidence of a foundation is all that remains just a few yards beyond the
tree line.  Photo was taken from the same front porch of the McLean house.