September 13, 2009, Mike West, The Murfreesboro Post
Constant communication was key to Union Army of the Cumberland’s success in Middle Tennessee.
Constant communication was key to Union Army of the Cumberland’s success in Middle Tennessee. And what was the secret behind that in the days before radio? The Army Signal and Telegraph Service. The object of the organization is to keep up constant communication between the different parts of the army and the different commanding generals, and to closely scan and discover the movements of the enemy. For this reason, the officers are furnished with powerful telescopes and marine glasses, and are usually located on the tops of high elevations, or other commanding positions, said John Fitch in his 1864 Annals of the Army of the Cumberland.
Gen. William S. Rosecrans organized the Signal Corps when he assumed command of the Army of the Cumberland. Rosecrans placed Capt. Jesse Merrill in charge. A Pennsylvania native, Merrill was an attorney by profession. Originally assigned to the Army of the Potomac, Merrill was reassigned to the Army of the Cumberland in January 1862 after learning the signal code.
When the Union Army marched from Nashville to Murfreesboro prior to the Battle of Stones River, Merrill and his Signal officers soon discovered they were at a disadvantage due to the terrain. Signals could not be used to any disadvantage on that field; woods and clumps of trees were all around us. Even if this had not been so, it would have been impossible to use them, for Gen. Rosecrans was constantly riding over the field, and other generals seemed equally active, wrote Merrill in a Jan. 7, 1863 report.
But soon after the battle, Merrill was able to set up a remarkable, for the day, communications system. Two Union brigades were dispatched to Readyville and to Cripple Creek to help protect the high ground on Pilot Knob, where Merrill established a signal station named Fort Transit. This emplacement commanded the highest point in the area and many items of interest and importance were reported by the officers on that station, Fitch said. Signal officers at Fort Transit were in constant communication with the Signal Corps center located in the cupola of the Rutherford County Courthouse. In those days, the courthouse was surmounted with a tall, brick clocktower. Two powerful telescopes were located in the clocktower. One was pointed toward Fort Transit while a second telescope covered communication stations at La Vergne and Triune.
To enable the reader more fully to understand the workings of the system, let him accompany the author to the signal-station in the cupola of the court-house at Murfreesborough, wrote Fitch. Here he will find two windows, one looking towards Fort Transit, nine and a half miles to the east, and the other towards Triune, seventeen miles to the west. By the side of each is a telescope, firmly fixed and bearing upon the station opposite.
Outside of the opening is a platform, upon which the man waving the flag or torch stands. It being desired to open communications, the flag is waved to and fro until seen and answered by the other station. Due to weather conditions, a variety of colored flags were used including black flags with white centers, white flags with red centers and flags that were all red.
Two teams, of four men and two officers, were assigned at all times at the Courthouse. Each message received was written down by an officer, and copies were kept. Most of them were short, 20 words or less, and took five minutes or less to send. A response took another five minutes or less.
Fitch cited an example of the speed of the transmissions. In March 1863, Gen. John M. Palmer advanced to Woodbury, 22 miles from Murfreesboro. Less than 30 minutes after the Union troops entered the town Rosecrans was informed by the Signal Corps. Rosecrans dispatched via signal certain orders to Palmer and within the hour had received word back that Palmer had received the order and dispatched his troops accordingly. In clear weather, messages could be sent directly from Pilot Knob to La Vergne, a distance of 25 miles, without being repeated at Murfreesboro or from Pilot Knob to Triune, which was 27 miles. This cut down on the transmission time.
Upon occasion, it was clear enough to transmit them directly from Pilot Knob to Nashville, 45 miles away. The Murfreesboro signal station was under command of Capt. C.R. Case of the 36th Indiana, and T.J. Kelly of the 10th Ohio Infantry. About 40 officers and 140 enlisted men were assigned to the Army of the Cumberland’s Signal Corps.