Commanding officer of the U.S. Army Signal Corps
The Chief Signal Officer of the United States Army was a position which was established during the American Civil War. Over the course of a century, the chief signal officer was the commanding officer of the U.S. Army Signal Corps which at various times was responsible for combat communications, strategic communications, military aviation, homing pigeons, designing and purchasing the Army's radio, radar, and other electronic equipment, weather reporting, Army photography and motion pictures, collection of signal intelligence, and research and development of technologies as diverse as wig-wag flag signaling, cryptography, FM radio, submarine cable, and satellite communications.
While the office of chief signal officer survived for a century, its responsibilities, role, and position in the Army and American society varied dramatically over time. The office evolved with changing technology, changes in America's role in the world, and the impact of major wars. The chief signal officer was frequently involved in policy discussions with Congress and the rest of the military over the breadth of his responsibilities and the role of the Signal Corps in the Army and American society. The office was eliminated in a 1964 reorganization.
Predecessor positions.
Signal officer (1860–1863).
Albert J. Myer was an Army doctor who proposed a new method of flag signaling in 1856. He was given a hearing on his idea by an examination board chaired by Lieutenant Colonel Robert E. Lee in 1859, and was authorized to conduct tests of his method. The tests were promising, and Myer appeared before the House and Senate Military Affairs Committees to describe them. In June 1860, Congress voted to fund one signal officer on the Army staff with the rank of major to pursue this work. Myer was appointed to the position. His role was to continue experimenting with signal technology to understand its potential usefulness to the Army. 
After the Civil War began, the signal officer took on new functional responsibilities. First and foremost, Myer placed signal teams in the field to support the fighting forces. In 1861 he was assigned to the Army of the Potomac, and began organizing its signal capability. In 1862 the role of the signal officer grew to include developing signal capability in all the Union Armies. By the end of the year there were 146 acting signal officers. An innovation of Myer's in 1862 was the development of portable field telegraph trains that could follow an army into battle.
In order to deploy signal teams to the field, men had to be trained. Myer implemented signaling training programs at both the U.S. Military Academy, and the U.S Naval Academy, as well as schools for training officers and men already in the Army. Myer's vision for communications included combined operations, and he developed links with the U.S. Navy which were tested at the Battle of Port Royal. 
Codes and encryption techniques for the Army were developed by the signal officer. Typically, signal stations were on high terrain so that they had a line of sight to the enemy positions they were surveilling. The Confederates could see the signal flags as clearly as the Union forces. The possibility of enemy interception of messages produced an immediate need for codes. Myer introduced simple cipher disks to encrypt messages.
Other than the signal officer, there were no men permanently assigned to signal duties. Generals would detach officers and men from their units for signal duty to be trained, equipped, and organized by Myer. This was unsatisfactory for several reasons, and the signal officer was involved in discussions with the Secretary of War and others as to how best to organize the new signaling function.
Signal Officer of the Army (1863–1866).
On 3 March 1863, in the midst of the Civil War, Congress enacted into law the position of Signal Officer of the Army. The authorization for this position was temporary, only for the duration of "the present rebellion." The Signal Officer of the Army was to have the rank of Colonel. Congress authorized a staff of one lieutenant colonel, and two majors who were to act as inspectors for the Signal Corps. Each Army Corps or military department was to have one captain, and as many lieutenants as the president saw fit to name, up to eight. 
Albert Myer was appointed to the new position. He took the Congressional mandate to mean that the signal officer of the Army should provide all the Army's communications, whether by flag, torch, or wire. This was contrary to the desires of Secretary of War Edwin Stanton. Not only was Myer removed from his post, but all of the wired telegraph services operated by the Signal Corps were transferred to a rival organization, the United States Military Telegraph Corps. For the remainder of the war, the signal officer of the Army oversaw only "aerial telegraphy", signal flags and torches.
Chief Signal Officer (1866–1964).
Post-Civil War organization.
After the Civil War, in 1866, Congress passed a law establishing the peacetime structure of the Army. The new law created the office of Chief Signal Officer of the Army as a permanent position with the rank of colonel, and gave the Secretary of War discretion to assign as many as 6 officers, and 100 non-commissioned officers and enlisted personnel to signal duty. Despite this Congressional support, the Signal Corps was all but disbanded in the immediate post-war period. In his 1866 annual report, Chief Signal Officer Fisher reported that his command had mustered out all personnel except those in his office. He auctioned off leftover material from the war. His job had become assembling records of Civil War operations for future historians.
The U.S. Military Telegraph Corps was abolished. In December 1865 the private telegraph lines which the government had seized at the beginning of the war were returned to their owners. The new lines built by the U.S. Military Telegraph Corps were sold to nearby private companies. By the end of 1866 all of its personnel had been reassigned or dismissed.
Weather organization (1870–1891).
In 1867 Myer was reappointed chief signal officer. He reimplemented a signaling curriculum at the US Military Academy, continued the development of cryptography, and, with the demise of the U.S. Military Telegraph Corps, regained authority over electric telegraphy. In 1870, Myer secured a major peacetime mission, weather reporting. Congress charged the secretary of war with taking weather observations throughout the country and providing warnings of impending storms. Myer was successful in having this responsibility assigned to the chief signal officer in War Department General Order 29, dated 15 March 1870. Citing the needs of commerce and agriculture for weather information, Congress appropriated $250,000 to support the Signal Corps weather reporting in 1872.
The weather reporting network relied heavily on commercial telegraph lines operated by Western Union and others. The need to include weather observation stations in remote areas, and a Congressional mandate to connect lighthouses and life-saving stations expanded the scope of the chief signal officer's responsibilities. He began building an extensive network of telegraph cables within the United States beginning in 1873. This network peaked at 5,077 miles in 1881, before the growth of commercial circuits and budget cuts forced the Signal Corps to begin retiring its lines. In June 1880, Congress raised the permanent rank of the chief signal officer to brigadier general, reflecting both its increased importance and parity with similar Army bureaus.
When Chief Signal Officer Greely took over in 1887, the weather bureau dominated Signal Corps activities. Military signaling had fallen into disuse and Secretary of War William C. Endicott reported that, "The Army has ceased to place reliance on the Signal Corps, but provides for its own instruction in military signaling." This issue persisted, and in his first state of the union message in December 1889, President Benjamin Harrison called on Congress to transfer the Weather Bureau to the Department of Agriculture, noting the deterioration of military signaling. Congress obliged in 1890 and the transfer of responsibility took place on 1 July 1891. The chief signal officer lost the civilian Weather Bureau, but maintained responsibility for weather reporting and forecasting for the Army.
Rebuilding military signaling (1891–1898).
The legislation which removed the Weather Bureau from the Signal Corps, also included explicit language as to the scope of the chief signal officer's responsibilities: "The Chief Signal Officer shall have charge, under the direction of the Secretary of War, of all military signal duties, ...the construction, repair, and operation of military telegraph lines, ...and the duty of collecting and transmitting information for the Army by telegraph or otherwise." The law provided for the Signal Corps to be composed of the chief signal officer, one major, four captains, four first lieutenants, and fifty sergeants.
Although the weather reporting network was gone, telegraph communications among coastal defense installations and between military bases remained within the purview of the chief signal officer. This included about 700 miles of lines in 1894. Appropriations for anything beyond personnel were small, but under Chief Signal Officer Greely, a number of technical innovations were explored. Experiments included observation balloons, telephones, light-weight field telegraph circuits, and training state reserve units in signaling. Future Chief Signal Officer James Allen was successful in duplexing telegraph and telephone circuits on the same wire. The commanding general of the Army referred to Greely favorably as "our enterprising chief signal officer."
Spanish-American War organization (1898–1899).
On 25 April 1898, Congress declared war on Spain, beginning the Spanish-American War. While Chief Signal Officer Greely had made progress in recovering the Signal Corps' military signaling capabilities, its 60 members were in no way adequate to support simultaneous offensives in Cuba, Puerto Rico, and the Philippines. The United States occupied Guam and annexed Hawaii that same year, adding further to the Army's communications requirements.
In May 1898, Congress authorized the president to create a volunteer signal corps to meet the new needs on a temporary basis for the duration of "the existing war." The Volunteer Signal Corps, which reported to the chief signal officer, was to consist of one colonel, one lieutenant colonel, one major, for each Army corps an additional major, and for each Army division up to two captains, two first lieutenants, two second lieutenants, fifteen sergeants, ten corporals, and thirty privates. Two-thirds of these men were to be skilled electricians or telegraphers. Just over 1,100 officers and men were inducted into the volunteer corps. They were organized into nineteen companies. The 15th Volunteer Signal Company reached Cuba, four companies of volunteers made it ashore in Puerto Rico, and two were dispatched to Manila. The war was over before the remainder of the volunteers could be deployed overseas.
The regular Army portion of the Signal Corps was enlarged during the conflict to include the chief signal officer, a colonel, a lieutenant colonel, two majors, five captains, nine first lieutenants, forty sergeants, fifty corporals, and three hundred privates. Many of the regular troops were dispersed to the volunteer companies to provide leadership to the recruits. Enough regulars remained for the chief signal officer to create four comapnies, designated A, B, C, and D. Companies A and D saw service in Puerto Rico.
Just as Lincoln had done in the Civil War, President McKinley nationalized all telegraph circuits in the United States for the duration of the war. The chief signal officer was given operational control of the networks. There was a particular focus on international cables which terminated in New York, Tampa, and Key West which might be used to transmit sensitive information to Spanish authorities. Enciphered messages and reporting on American troop movements were banned. The plain-text messages that remained were harvested for intelligence, which may have played a role in the destruction of the Spanish fleet in Cuba. The chief signal officer was, for a time, America's chief censor and signals intelligence officer. 
At the conclusion of hostilities, the Volunteer Signal Corps companies were mustered out at various times in 1898 and 1899. 
Global expansion (1899–1903).
The acquisition of the Philippines, Cuba, Puerto Rico, Guam, and Hawaii in 1898 transformed America into a global empire. The discovery of gold on the Klondike and at Nome made Alaska another new center of American interest at the same time. This global expansion of American interests brought global responsibilities to the chief signal officer.
In Cuba and Puerto Rico, the chief signal officer took over all the communications networks on the islands during the military occupation after the surrender of the Spanish. Some telephone