WORLD WAR 2 IN REVIEW: U.S. Army Organization, 1941

by Fleming MacLiesh and Cushman Reynolds

Published in 1941

The U.S. Army, even in 1941, was an almost inconceivably complex organization. Its multitudinous details, carried in the head of no one man, converged in the General Staff. Here the chiefs of the various departments met and pooled their information under the direction of the Chief of Staff to plan a campaign or decide on a course of action and integrate in a striking force the various heavily organized branches of which the Army was even then composed.

At the top of this organization was the General Staff, organized along German lines in 1903 and war-tested in 1917. It was then headed by the Chief of Staff, General George C. Marshall. It was his function, under the Secretary of War, to plan, develop and exercise the Army program for National Defense. He had six brigadier generals to help him.

The two Deputy Chiefs of Staff were the alter egos of the Chief, taking charge when he was away, and are adjutant or liaison men with the other five. The Staff proper had five divisions.

War Plans Division: It planned strategy, tactics, the use of the Army in war, and estimated its required size.

G-1: Devoted to plans and policies in regard to personnel from recruiting to discharge; it dealt with such things as pay, promotions, recreation and religion.

G-2—Military Intelligence: It collected, analyzed, and passed out military information for the Army. Its activities ranged from the observations of our military attaches at foreign capitals, to breaking down codes and ciphers, organizing and utilizing the work of spies and making use of other channels of possible military information.

G-3: Concerned with training and operating the Army in the field. In one sense, it was the backbone of the Staff. It was, at the time, under the first Air Corps officer ever to head a General Staff division.

G-4—Supply: It had charge of planning and procuring all equipment, buildings, storage and the transportation and distribution of supplies. It had charge of caring for the sick and wounded and was accountable for all Army property and leased and maintained real estate.

The Army consisted of three forces: the Regular Army, the National Guard, and the Organized Reserves.

In accordance with the National Defense Act of 1920 the country was divided into nine corps areas for administrative purposes.

The first corps area comprised Connecticut, Massachusetts, New Hampshire, Rhode Island, Vermont and Maine.

The second: Delaware, New Jersey and New York.

The third: District of Columbia, Maryland, Pennsylvania and Virginia.

The fourth: Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee.

The fifth: Indiana, Kentucky, Ohio and West Virginia.

The sixth: Illinois, Michigan and Wisconsin.

The seventh: Arkansas, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota and South Dakota.

The eighth: Arizona, Colorado, New Mexico, Oklahoma and Texas.

The ninth: California, Idaho, Montana, Nevada, Oregon, Utah, Washington and Wyoming.

These nine corps areas were, for strategic organization, grouped into four Army regions each commanded by a lieutenant general.

The 1st was composed of the 1st, 2nd and 3rd Corps areas; the 2nd of the 5th and 6th Corps areas; the 3rd of the 4th and 8th Corps areas; the 4th of the 7th and 9th Corps areas.

The overseas departments were: the Hawaiian Department, the Philippines Department, the Panama Canal Department, and the Puerto Rican Department.

The territory of Alaska was attached to the Ninth Corps area.

The Regular Army, whatever its between-the-wars peacetime size-and it shrank in the 1920s and 1930s to some 100,000 officers and men-was regarded as a thoroughly trained skeleton force, which could envelop and absorb and develop the large number of volunteers and draftees poured in when an emergency came.

The Army was divided into units as follows:

Squad: Commanded by a sergeant or corporal.

Section: Commanded by a sergeant.

Platoon: Commanded by a lieutenant, first or second, corresponds to a "sub-flight" in the Air Corps.

Company: Commanded by a captain, it corresponded to a "battery" in the Field and Coast Artillery; to a "troop" in the Cavalry; and to a "flight" in the Air Corps.

Battalion: Commanded by a lieutenant colonel or a major, it corresponded to a "squadron" in the Cavalry and Air Corps.

Regiment: Commanded by a colonel, it corresponded to a "group" in the Air Corps.

Brigade: Commanded by a brigadier general, it corresponded to a "wing" in the Air Corps (it was found only in the Infantry, Cavalry, Field and Coast Artillery; it was not included in the "streamlined" division).

Division: Commanded by a major general.

Corps: Often called "Army Corps," it was commanded by a lieutenant general.

Army: Often called a "Field Army," commanded by a general.

The Arms

Infantry

The Infantry unit was the division, and in the U.S. Army of the period, there were two types of division. The old "square" division consisted of two infantry brigades, of two regiments each, a brigade of three regiments of supporting artillery, one regiment each of engineer, quartermaster, and medical troops, smaller units of ordnance and signal corps specialists-a total of approximately 18,500 men. The new and smaller "streamlined" triangular division consisted of three infantry regiments, two regiments of supporting field artillery, one battalion each of engineer, medical and quartermaster troops and a company of signal corps troops, a total wartime strength of about 12,500 men. Infantry weapons included the .30-caliber rifle, semi-automatic rifle, automatic rifle, and machine gun, the .50-caliber machine gun, the 37-mm anti-tank gun, 60-mm mortar, 81-mm mortar, .45-caliber pistol, and hand grenade.

Cavalry

The Cavalry, at that time still mainly horse-mounted, was in a gradual process of mechanization, although a certain amount of horse cavalry was to have been retained. (The Army contended that motor vehicles were not of much use along the southern U.S. border and through much of the difficult terrain of the Western Hemisphere.) The regular cavalry division was reorganized to contain 600 officers and 9,500 men-in place of 500 and 8,500 respectively-the number of horses being cut from 8,000 to 6,000, and the number of motor vehicles upped from 350 to 800. The horse-mounted regiment contained regimental headquarters and service troops, machine gun troop, special weapon troop, and rifle troops. The weapons of the cavalry-horse and mechanized-were pistol, rifle, .30-caliber air-cooled machine gun, .30-caliber water-cooled machine gun, .45-caliber submachine gun, .50-caliber machine gun, 37-mm gun and four .2-inch mortar firing smoke shells as a defense against anti-tank weapons. The mechanized cavalry regiment contained headquarters and service troop, recon troop, machine gun troop and combat car troops. Vehicles, combat and service, of the mechanized cavalry were combat cars (light tanks), motorcycles (solo and with sidecar), scout cars, command-recon trucks, pickup trucks, cargo trucks, tractor trucks with semi-trailers, and wrecker trucks. Two regiments of mechanized cavalry were formed into one brigade with supporting units of mechanized field artillery.

Field Artillery

The Field Artillery supported the main fighting arms, the Infantry and Cavalry. It gave this support through the firepower of its cannon, classified as guns and howitzers. A gun fired a shell over a long range with a comparatively flat trajectory; a howitzer fired shells which curved high in the air and could thus be dropped on enemy positions hidden behind hills, etc. According to the caliber of weapons, Field Artillery units were classified as light, medium and heavy artillery. The light artillery fired the 75-mm gun and the 105-mm howitzer, which could be horse-drawn or truck-drawn, and the 75-mm howitzer, which could also be pack-carried. The medium artillery fired the 155-mm howitzer which was truck-drawn. The heavy artillery fired 155-mm guns, 8-inch howitzers and 240-mm howitzers. At the time, the 75-mm gun was being replaced by a new and larger 105-mm howitzer for the triangular field divisions. Divisional artillery for those consisted of three battalions of 105-mm howitzers and one battalion of 155-mm howitzers. At the time all National Guard artillery had been motorized.

Coast Artillery

The Coast Artillery Corps manned the fixed guns, from 3- to 16-inches, of our harbor and coastal defenses and such bases as the Canal Zone and Pearl Harbor, mobile motorized artillery and railway guns, its own anti-aircraft artillery, and the land-based and land-controlled mines laid in channels offshore. Its function was to protect the important parts of our shores and bases, mainly entrances to harbors and ports from naval bombardment and approach by invading troops. It acted, therefore, in close cooperation with the U.S. Navy.

Coast Artillery regiments were of two kinds-harbor defense and anti-aircraft. Harbor defense regiments were divided according to function. Some operated the fixed guns; these ranged from 3-inch guns firing a 15-pound shell to 16-inch guns firing a shell weighing more than a ton 20-odd miles out to sea. These big guns were considerably more accurate than comparable guns mounted on ships. Fixed guns were of three main classifications: 12-, 14- and 16-inch; 6-, 8- and 10-inch guns; and 12-inch high-firing mortars.

Other regiments of the harbor defense operated railway and tractor- or truck-drawn guns for defense against landings attempted at points not covered by the fixed defenses. The motor-drawn units fired a 155-mm gun. The weapons of the railway artillery units were mounted on special railway cars. Capable of moving along any of the country's standard rail lines or of being run out, where need be, on special spurs, they included 8-inch guns, 12-inch mortars and heavy 14-inch guns.

Anti-aircraft units of the Coast Artillery used the 3-inch anti-aircraft gun for long-range firing, the 37-mm anti-aircraft gun and the .50-caliber machine gun for short-range defense against low-flying or "hedge-hopping" planes. The guns were supplemented by searchlights of approximately 800,000,000 candlepower, rangefinders, sound detectors, etc. Then coming into use with the anti-aircraft regiments was the 90-mm anti-aircraft gun—considerably more accurate than the 3-inch—and radar (then referred to as "secret ray-detector" or "black light"), of which production had only just begun.

The Tank Corps

The Army was using three main types of tanks: light, medium and heavy. Light tanks were classified as weighing between 8 and 15 tons, medium tanks between 15 and 30 tons, and heavy tanks, 30 tons and over.

The outline of the Tank Corps was to follow a pattern established in the summer of 1940 with the formation of a cadre comprising the Infantry and the Cavalry's 7th Mechanized Brigade. This cadre was responsible for maintenance, development and operations of tanks, separated from the Infantry and Cavalry and under one head with its representative on the General Staff.

The Corps of Engineers

Technical engineering skill in peace or war was furnished by the Corps of Engineers. It was also a fighting arm; when the need for reserves for combat troops is more urgent than the need for engineering, the Combat Engineers go into action like the Infantry. Their war tasks included building, maintaining, and repairing buildings, bridges, and structures of every kind except those within the province of the Signal Corps. Among their functions were surveying and mapping, the latter including not only topographical plotting but actually printing and producing maps. They would conduct military mining, blow up bridges, viaducts and roads when necessary, and even destroying captured enemy materiel. Theirs was the task of Army road construction, maintenance and repair in wartime. Engineers operated railroads, electric light and power systems, water supply systems and other utilities; they obtained, stored and issued all materials for construction, for defense installations, for all other engineering work, including the plants, appliances and tools required. Engineering units were then largely motorized.

The Signal Corps

Army communications of all kinds were the province of the Signal Corps. These included messages sent by airplane, motorcycle, homing pigeon, telephone, teletype, telegraph and radio. The Signal Corps also developed, produced and supplied signal, meteorological and photographic equipment for the Army. When a break in communications occurred through enemy activity, Corps units had to repair it under fire if necessary, which made the Signal Corps also a combat arm. It operated commercial-type telephones, switchboards, teletypes, etc., in the rear zone and as far to the front as commercial power plants could provide service; it operated in the war zone its own specially designed field telephones, telegraph and radios. Through a net of 146 fixed, Army-operated radio stations, the War Department could keep in touch with the whole U.S. Army both in this country and overseas.

The Services

Behind the fighting arms stands the services, as follows:

The Adjutant General's Department: Assisted the Army's high commanders in the issuance of orders and in the management of the Army's daily business.

The Inspector General's Department: Inspected and investigated all posts, camps, barracks, Army schools, transports, recruiting stations, Army finances, etc., and made specific criticism and suggestions for Army improvement.

Judge Advocate General's Department: Had charge of all legal matters in which the Army was concerned, all legal matters within the Army, such as trials by courts martial, etc.

The Quartermaster Corps: Would obtain and furnish food, clothing and equipment of various kinds. It would build and maintain temporary and permanent housing—including cemeteries—for all the arms and services. It also had charge of transporting the Army by rail and water.

The Ordnance Department: Would design, obtain and distribute to the fighting arms the weapons and ammunition with which they would fight. It had charge of improving existing weapons and developing new ones. Under it were the six Army arsenals where weapons were manufactured and which supplied the Army with most of the ordnance needed in peacetime.

The Chemical Warfare Service: Its tasks were the development and supply of gases, smokes, and incendiary materials, and of the weapons from which to fire them; the training of special gas troops-using the chemical mortar, the Livens projector and the portable chemical cylinder; and devising protection against enemy chemicals.

The Finance Department: Would disburse and account for the funds appropriated by Congress for the Army, paying the salary of all War Department personnel and the amounts due...from an order for several hundred planes to an allotment of shoes...for all Army purchases.

The Medical Department: Maintained the Army's health, and administered to its sick and wounded, and the hospitals.

The Corps of Chaplains: Charged with caring for the spiritual and moral needs of the Army. Chaplains were selected from various religious denominations in proportion to the number of members of these denominations in the Army as a whole.

The New Army

Though the New Army was not then completely plotted, its basic form had begun to take shape. During the summer of 1940 the Regular Army was expanded to include nine infantry divisions, one cavalry division, and two armored divisions. The minimum initial goal with the National Guard in service was nine Army corps, each corps to consist of two "square" divisions and one "triangular" division. The 27 infantry divisions thus formed were to be supported by necessary corps, Army and GHQ units, including horse-mounted cavalry divisions and four armored or mechanized divisions. The total strength of this initial force was to have been about 850,000 men.

The square divisions were to be formed form National Guard units and being less highly mechanized would require less lengthy and constant training as the triangular divisions. Their function was to follow up and hold positions taken by the triangular and armored divisions.

The triangular division, one to each two square divisions, would be formed form the Regular Army. War strength would be about 4,500 men less than that of the square division. Each triangular division would get a mechanized unit of armored scout cars and motorcycles for reconnaissance, and divisional artillery was also reorganized, with the 105-mm howitzer replacing the old 75-mm field gun (the latter being relegated to anti-tank duties). Some of the triangular divisions were to have been trained for special duties: one, perhaps, for landing operations, while another might have been completely motorized to work with armored divisions.

The armored divisions were generally patterned after the German panzer division which some U.S. Army officers predicted as far back as 1930. At the time an expansion to 84,000 enlisted men and 20,000 vehicles (an increase of 1,200% over the nucleus) was envisaged within the year, with an initial goal of four armored divisions with ten GHQ tank battalions. The war strength of each armored division was to have been 11,500 men with 19,000 weapons, 2,500 vehicles and a division headquarters troop, signal troop, a squadron (thirteen) of observation planes, reconnaissance battalion, tank brigade, a mechanized field artillery regiment plus a field artillery battalion, a motorized infantry regiment with attached ordnance, quartermaster and other troops, 272 light tanks, 110 medium tanks, 201 armored scout cars, twenty-seven 75-mm howitzers, twelve 105-mm howitzers, eight 75-mm guns. At the time this entire armored force was under the command of an Armored Field Force Commander, General Adna R. Chaffee. Ten divisions were then projected.

An Air Defense Command was formed in early 1940, with headquarters at Mitchel Field on long Island to cooperate with coast and anti-aircraft defense and home defense units. They were responsible for shaping the aircraft warning system utilizing radar and commercial telephone hook-up.

The 34th Infantry Division, composed of National Guard troops, forms up on the Camp Claiborne, Louisiana, parade ground, circa 1941, to participate in Louisiana Maneuver training. The division was the first large-scale U.S. military unit to be sent to the ETO.

U.S. Army soldiers training at Fort Belvoir, Va., May 1941. Library of Congress.

Anti-tank Battalion, 30th Division, battle with tanks of the 2nd Armored Division, during Carolina maneuvers. Tank in background was put out of action. South of Peedee River, Cheraw, South Carolina, 19 November 1941.

Horse cavalry with M3 light tank during Louisiana maneuvers, 1941.

Soldiers relax with some Blatz Beer during downtime between exercises at the 1940 Louisiana Maneuvers.

M2A2 light tanks. The Louisiana Maneuvers allowed combat commanders to test out armored warfare doctrine in 1940.

The Army used explosives to enhance river crossings during the 1941 Louisiana Maneuvers.

The Army found horses unsuitable for modern warfare during the 1940 and 1941 Louisiana Maneuvers.

Battery B, 21st Field Artillery stands ready with its M1917 155mm howitzer near Simpson during the Louisiana Maneuvers in 1941.

In one of the earliest photos from the Louisiana Maneuvers, soldiers march in formation in May 1940. Note they still wear the World War I-style helmet and necktie.

M2A3 light tank at the Army Day parade in Washington, D.C., 6 April 1939. Library of Congress.

M2A2 light tank, Washington, D.C.

Crude and slightly unconvincing perhaps ... but they served their purpose. Infantry training with "tanks" at Ft. Benning.

6th Infantry, 27th Field Artillery observation post, Fort Knox, Kentucky, 1941.

75mm gun defending town of Lake Charles against tank attack during Third Army maneuvers in Louisiana, September 11, 1941.

155mm howitzer in action during training.

155mm howitzer, circa 1941.

155mm howitzer.

A U.S. Army corporal of the 3rd Infantry Division stands at attention with a group of women in two-piece bathing suits wearing M1917 helmets and holding M1917 Enfield rifles in Camp George Derby at the California Pacific International Exposition in San Diego's Balboa Park, 1935.

Original caption: Soldiers inspecting new trackless tank during demonstration at Fort Myer, Virginia. Tank was manufactured by the Trackless Tank Corporation of New York, and submitted to the Ordnance Department, U.S. Army, for inspection. Preliminary tests indicate that the tank may be adaptable for reconnaissance purposes, possibly replacing scout cars. April 1941. Library of Congress.

Soldiers of headquarters company of the Armored Corps lifting a jeep to repair it at their bivouac area during Second Army maneuvers, June 1941. Library of Congress.

Men from Company G, 182nd Infantry Regiment, on a field exercise at some point during 1941.

Members of Company D, 192nd Tank Battalion, Kentucky National Guard, pose with their vehicles at Ft. Knox, Ky., during the unit's training prior to World War II. Called into federal service pursuant to the national emergency declared by President Franklin D. Roosevelt in 1940, the 192nd, along with the Guard's 194th Tank Battalion, were deployed to reinforce the Army garrison of the Philippines.

Communications sergeant preparing communication equipment during the Louisiana Maneuvers of 1941.

Mail call in the field during the 1941 Louisiana Maneuvers.

Addison's store pictured as it was flour bombed during the Battle of Mt. Carmel during the Louisiana maneuvers in 1941.

Gathering of officers in the field during the Louisiana maneuvers in 1941. The officer on the right is Colonel Dwight Eisenhower.

M2A2 light tank in action at Special Demonstration for members of Congress at Fort Belvoir, Va., 2 October 1941.

Major General Bruce Magruder, Commanding General of the 1st Armored Division (by machine gun in Scout Car), issues orders to his unit commanders who are gathered about the map. Fort Knox, Kentucky, 26 March 1941.