United States Army Signal Corps

In 1881, the Signal Corps participated in the First [[International Polar Year]]. One of the groups commanded by Lieutenant Greely became separated from their base camp and were [[Marooning|marooned]] on an [[ice floe]]. Due to starvation and drowning, only seven of the original 25 volunteers survived, meaning a 28% chance of surviving.

In 1881, the Signal Corps participated in the First [[International Polar Year]]. One of the groups commanded by Lieutenant Greely became separated from their base camp and were [[Marooning|marooned]] on an [[ice floe]]. Due to starvation and drowning, only seven of the original 25 volunteers survived, meaning a 28% chance of surviving.

The Signal Corps aided in the [[Spanish–American War]] of 1898 and the subsequent [[Philippine–American War|Philippine Insurrection]]. In addition to visual signalling, including [[heliograph|heliography]], the corps supplied telephone and [[Electrical telegraph|telegraph wire lines]], cable communications, enabled the use of telephones in combat, conducted [[War photography|combat photography]], and renewed the use of balloons. Shortly after the war, the Signal Corps constructed the [[Alaska Communications System (ACS)|Washington-Alaska Military Cable and Telegraph System (WAMCATS)]], also known as the [[Alaska Communications System]] (ACS). This was the first wireless telegraph in the [[Western Hemisphere|Western Hemisphere.]]

The Signal Corps aided in the [[Spanish–American War]] of 1898 and the subsequent [[Philippine–American War|Philippine Insurrection]]. In addition to visual signalling, including [[heliograph|heliography]], the corps supplied telephone and [[Electrical telegraph|telegraph wire lines]], cable communications, enabled the use of telephones in combat, conducted [[War photography|combat photography]], and renewed the use of balloons. Shortly after the war, the Signal Corps constructed the [[Alaska Communications System (ACS)|Washington-Alaska Military Cable and Telegraph System (WAMCATS)]], also known as the [[Alaska Communications System]] (ACS). Contemporary accounts described this as among the first wireless telegraph systems in the Western Hemisphere.{{Template:Citation needed|date=April 2026}}

In October 1903, Congress directed then Chief Signal Officer Brigadier General [[Adolphus Greely]] to issue an order. In October 1904, Congress appropriated $25,000 for the Signal Corps to "build a flying machine for war purposes."{{Cite web |last=Taylor |first=Mike |date=1962-06-01 |title=20th Anniversary of Army Aviation – Part I – Cannon Field 53T |url=https://als-cannonfield.com/index.php/1962/06/01/20th-anniversary-of-army-aviation/ |access-date=2026-01-09 |language=en-US}} Chief Signal Officer Brigadier General Adolphus Greely thus contracted the [[Wright brothers]] in 1908, who piloted the first aircraft at [[Kitty Hawk, North Carolina]].

In October 1903, Congress directed then Chief Signal Officer Brigadier General [[Adolphus Greely]] to issue an order. In October 1904, Congress appropriated $25,000 for the Signal Corps to "build a flying machine for war purposes," directing Chief Signal Officer Brigadier General Adolphus Greely to oversee the effort.{{Cite web |last=Taylor |first=Mike |date=1962-06-01 |title=20th Anniversary of Army Aviation – Part I – Cannon Field 53T |url=https://als-cannonfield.com/index.php/1962/06/01/20th-anniversary-of-army-aviation/ |access-date=2026-01-09 |language=en-US}} Chief Signal Officer Brigadier General Adolphus Greely thus contracted the [[Wright brothers]] in 1908 to build and demonstrate a military airplane; the Wrights conducted their trials at Fort Myer, Virginia. Their historic first powered flight had taken place at [[Kitty Hawk, North Carolina]], in December 1903.

=== World War I ===

=== World War I ===

{{Further|Aeronautical Division, U.S. Signal Corps|Aviation Section, U.S. Signal Corps}}

{{Further|Aeronautical Division, U.S. Signal Corps|Aviation Section, U.S. Signal Corps}}

In 1941, the laboratories at Fort Monmouth developed the [[SCR-300]], the first [[FM broadcasting|FM]] backpack radio. Its [[frequency modulation]] circuits provided front-line troops with reliable, static-free communications. The labs also fielded multichannel FM radio relay sets (e.g., AN/TRC-1) in the [[European Theater of Operations]] as early as 1943. Multichannel radio broadcasting allowed several channels of communications to be broadcast over a single radio signal, increasing security and range and relieving [[frequency spectrum]] crowding.

In 1941, the laboratories at Fort Monmouth developed the [[SCR-300]], the first [[FM broadcasting|FM]] backpack radio. Its [[frequency modulation]] circuits provided front-line troops with reliable, static-free communications. The labs also fielded multichannel FM radio relay sets (e.g., AN/TRC-1) in the [[European Theater of Operations]] as early as 1943. Multichannel radio broadcasting allowed several channels of communications to be broadcast over a single radio signal, increasing security and range and relieving [[frequency spectrum]] crowding.

In December 1942, the War Department directed the Signal Corps General Development Laboratories and the [[Camp Evans]] Signal Lab to combine into the Signal Corps Ground Service (SCGS) with headquarters at [[Bradley Beach, New Jersey]] (Hotel Grossman). The department also directed the Signal Corps Ground Service to cut total military and civilian personnel from 14,518 military and civilian personnel to 8,879 by August 1943.{{Citation needed|date=March 2026}} In June 1944, "Signees", former Italian [[prisoner of war|prisoners of war]], arrived at Fort Monmouth to perform housekeeping duties. A lieutenant colonel and 500 enlisted men became hospital, mess, and repair shop attendants, relieving American soldiers from these duties.

In December 1942, the War Department directed the Signal Corps General Development Laboratories and the [[Camp Evans]] Signal Lab to combine into the Signal Corps Ground Service (SCGS) with headquarters at [[Bradley Beach, New Jersey]] (Hotel Grossman). The department also directed the Signal Corps Ground Service to reduce its workforce from 14,518 to 8,879 personnel by August 1943.Thompson, et al. ''The Signal Corps: The Test'', pp. 220-225. In June 1944, "Signees", former Italian [[prisoner of war|prisoners of war]], arrived at Fort Monmouth to perform housekeeping duties. A lieutenant colonel and 500 enlisted men became hospital, mess, and repair shop attendants, relieving American soldiers from these duties.

[[File:SCR188.jpg|right|thumb|Radio operator Cpl. John Robbins, 41st Signal, 41st Infantry Division, operating his SCR-188 in a sandbagged hut at Station NYU. Dobodura, [[New Guinea]] on 9 May 1943.]]

[[File:SCR188.jpg|right|thumb|Radio operator Cpl. John Robbins, 41st Signal, 41st Infantry Division, operating his SCR-188 in a sandbagged hut at Station NYU. Dobodura, [[New Guinea]] on 9 May 1943.]]

=== Korean War and Vietnam War ===

=== Korean War and Vietnam War ===

During the [[Korean War]] and [[Vietnam War]] the Signal Corps operated officer candidate schools initially at Fort Monmouth in 1950–1953, graduating 1,234 officers, and at [[Fort Gordon]] in 1965–1968, which produced 2,213 signal officers (The World War II Signal OCS program at Fort Monmouth, from 1941 to 1946, graduated 21,033 Signal Corps officers).{{Citation needed|date=April 2026}}

During the [[Korean War]] and [[Vietnam War]] the Signal Corps operated officer candidate schools initially at Fort Monmouth in 1950–1953, graduating 1,234 officers, and at [[Fort Gordon]] in 1965–1968, which produced 2,213 signal officers (The World War II Signal OCS program at Fort Monmouth, from 1941 to 1946, graduated 21,033 Signal Corps officers).Raines, Rebecca Robbins, ''Getting the Message Through: A Branch History of the U.S. Army Signal Corps'', Center of Military History, United States Army, Washington, D.C., 1999.

Modern warfare utilizes three main types of signal soldiers. Some are assigned to specific military bases ("Base Ops"), and they are charged with installation, operation, and maintenance of the base communications infrastructure along with hired civilian contracted companies. Others are members of non-signal Army units, providing communications capability for those with other jobs to accomplish (e.g. infantry, medical, armor, etc.) in much the same way as, say, the unit supply sections, unit clerks, or chemical specialists. The third major type of signaler is one assigned to a signal unit. That is to say, a unit whose only mission is to provide communications links between the Army units in their area of operations and other signal nodes in further areas served by other signal units.

Modern warfare utilizes three main types of signal soldiers. Some are assigned to specific military bases ("Base Ops"), and they are charged with installation, operation, and maintenance of the base communications infrastructure along with hired civilian contracted companies. Others are members of non-signal Army units, providing communications capability for those with other jobs to accomplish (e.g. infantry, medical, armor, etc.) in much the same way as, say, the unit supply sections, unit clerks, or chemical specialists. The third major type of signaler is one assigned to a signal unit. That is to say, a unit whose only mission is to provide communications links between the Army units in their area of operations and other signal nodes in further areas served by other signal units.

A major program in 1988 was the initial production and deployment of the mobile-subscriber equipment (MSE) system. The MSE system called for setting up the equivalent of a [[Mobile phone|mobile telephone]] network on a battlefield, allowing a commander or [[Tactical Operations Center]] (TOC) to connect mobile telephones and fax machines in vehicles with each other, sending and receiving secure information. Talking through signal nodes, MSE established a seamless connection from the battlefield even back to [[Commerce|commercial]] telephone lines. Significant to the Signal soldiers, MSE was fielded on the backs of [[Humvee]], rather than on the larger, less-mobile [[M35 2-1/2 ton cargo truck|M35 2½-ton cargo truck]]s—the "deuce and a half".Raines. pp. 394–95.

A major program in 1988 was the initial production and deployment of the mobile-subscriber equipment (MSE) system. The MSE system called for setting up the equivalent of a [[Mobile phone|mobile telephone]] network on a battlefield, allowing a commander or [[Tactical Operations Center]] (TOC) to connect mobile telephones and fax machines in vehicles with each other, sending and receiving secure information. Talking through signal nodes, MSE established a seamless connection from the battlefield even back to [[Commerce|commercial]] telephone lines. Significant to the Signal soldiers, MSE was fielded on the backs of [[Humvee]], rather than on the larger, less-mobile [[M35 2-1/2 ton cargo truck|M35 2½-ton cargo truck]]s—the "deuce and a half".Raines. pp. 394–95.

By 1990, most Army units had replaced their older [[AN/VRC-12|VRC-12]] series FM radios for the new [[SINCGARS]] ("Single-Channel Ground-Air Radio Systems") family of equipment. Rather than sending a signal along one [[Frequency|signal frequency]], the SINCGARS radios sent their signals across many frequencies, [[Frequency-hopping spread spectrum|"hopping"]] from one frequency to another at high speed. This allowed many nets to share an already-crowded [[Spectral density|frequency spectrum]].Center for Army Lessons Learned (CALL) Newsletter No. 92-1, ''Operations Desert Shield – Desert Storm'', Jan. 1992. P. 4. Later generations of these radios combined the [[communications security]] (COMSEC) encryption devices with the receiver/transmitter, making a single easier-to-program unit. Most significant, the SINCGARS radios could send and receive digital traffic with great fidelity.Raines. pp. 396–7. By the advent of [[Gulf War|Operation Desert Shield]], all Army units deployed were using the most secure FM communications in the world. The SINCGARS radios have a failure rate in extreme heat of once every 7,000 hours compared to the VRC-12 series' failure rate of 200–300 hours.Raines. p. 407.

By 1990, most Army units had replaced their older [[AN/VRC-12|VRC-12]] series FM radios for the new [[SINCGARS]] ("Single-Channel Ground-Air Radio Systems") family of equipment. Rather than sending a signal along one [[Frequency|signal frequency]], the SINCGARS radios sent their signals across many frequencies, [[Frequency-hopping spread spectrum|"hopping"]] from one frequency to another at high speed. This allowed many nets to share an already-crowded [[Spectral density|frequency spectrum]].Center for Army Lessons Learned (CALL) Newsletter No. 92-1, ''Operations Desert Shield – Desert Storm'', Jan. 1992. P. 4. Later generations of these radios combined the [[communications security]] (COMSEC) encryption devices with the receiver/transmitter, making a single easier-to-program unit. Most significant, the SINCGARS radios could send and receive digital traffic with great fidelity.Raines. pp. 396–7. By the advent of [[Gulf War|Operation Desert Shield]], all deployed Army units had transitioned to SINCGARS, then considered among the most secure tactical FM communications systems available.Raines. p. 407.. The SINCGARS radios have a failure rate in extreme heat of once every 7,000 hours compared to the VRC-12 series' failure rate of 200–300 hours.Raines. p. 407.

=== Afghanistan and Iraq ===

=== Afghanistan and Iraq ===