From the Napoleonic Era through the end of WWII, the basic model of large scale land warfare was of the mobilization army. That is, a small professional army in peacetime would vastly expand in time of war by means of conscription of a major swath of the military aged male population. The standing army would provide the framework upon which to build new units, and the command structure of corps, armies and theater headquarters.
For most of this era, the regiment was the standard formation raised. Roughly 1000 men strong, and virtually all of it infantry, as little as a few weeks of drill would suffice as training before a conscription regiment was considered fit for duty.
But by the time of the beginning of World War II, the US Army had evolved its doctrine to embrace combined arms, especially the integration of infantry with artillery as a team. Further, advances in motorization, signals, and engineering, coupled with a shift to the division as a standing permanent formation, as well as being the primary tactical formation, meant that rather than simply raising regiments, the Army would focus on raising divisions, training them as a single unit, and once trained, deploying that entire division overseas to a theater commander as an integrated tactical unit.
First, let us take a quick look at the Army’s triangular infantry division. The division consisted of a headquarters, three Infantry regiments, a Division Artillery of roughly regimental size, and the Division troops, with such diverse units as the Engineer Combat Battalion, the Medical Battalion, the Cavalry Reconnaissance Troop, Quartermaster, Ordnance, and Signal companies, and a Military Police Platoon.
All total, the division would have a strength of just over 14,000 officers and men. And virtually the entirety of the divisions men would be draftees with absolutely no military experience. The division would have to train them both in the most basic of military skills, then for the specialty the Army intended for them at an individual level, and finally, once some semblance of individual skills had been imparted, begin training the component units as units.
A couple months before a division was activated, the head of Army Ground Forces, LTG Leslie McNair, would sit down with the head of Army personnel and pick the future Division Commander, the Assistant Division Commander, and the Division Artillery Commander; that is, the three general officers of a division, one Major General, and two Brigadier Generals. Those officers would be sent to a short course at the Army’s Command and General Staff School to be indoctrinated on the organization, training, and tactical employment of the division
Concurrently, a cadre of about 1300 officers and senior NCOs would be selected from an existing division to form the skeleton of the new division. For instance, the Division staff, the commanders of the various regiments and battalions, and key positions in their staffs would be named. This cadre would also undergo training in anticipation of the division’s activation, but with more an emphasis on how to train the draftees that would shortly come into their charge.
The great majority of divisions raised for the war were infantry divisions McNair’s AGF laid out a standard training schedule that divisions would follow. Lasting roughly one year, at the end of a crawl-walk-run approach to unit training, AGF would have produced a division that it could release for embarkation overseas to a theater commander.
17 weeks of basic and advanced training
13 weeks of unit training
14 weeks of combined arms training and large-scale exercises
8 weeks of final training
The first 17 weeks would be devoted to what today we would call Initial Entry Training. Rather than conducting basic training at another post and then joining the division, here the division bootstrapped its own basic training course, over about 8 weeks, and then conducted what amounted to Military Occupational Specialty training for the many, many different jobs in the division.
The 13 weeks of unit training would quickly build from the team to the battalion level. Examples might start small, such as the rifle squad in the defense, then quickly grow to an entire company live fire attack course.
Fourteen weeks of combined arms training was where the division’s regiments began integrating with the supporting divisional artillery battalions, forming the Infantry/Artillery team that was the heart of the division’s combat power. See also this link.
The final 8 weeks of training ideally saw the entire division maneuvering as a single unit, and exercised not just the combat troops, but also the logistical elements of the division. And of course, as larger and larger units maneuvered, the staffs and headquarters of those units became more familiar with how to best employ them.
The Chief of Staff of the Army, GEN George Marshall, was a great believer in large-scale, force on force maneuvers. During unit and combined arms training, the various companies, battalions and regiments of a division could square off against one another. Eventually, the division would conduct maneuvers against another division going through its own mobilization and training.
Having completed its year long training schedule, the division would continue training at various levels until such time as it was alerted for embarkation and deployment.
Two other major ingredients were needed for the division’s recipe. One was equipment. The other was a post, or cantonment for the troops to live and train on. Personnel turbulence would also have a major effect on a division’s ability to constitute itself and train for deployment.
The common perception today is the the US simply produced vast quantities of all the material needed for war. And to be sure, the US did pull off a miracle of manufacturing. But in the early stages of mobilization, the production of equipment was not yet vast enough to equip units as they were activated. Typically, as a division was planned for activation, the Quartermaster Corps would begin planning to issue all the thousands of different pieces of equipment a division would need, from uniforms to rifles, to trucks, artillery pieces, signal wire for field telephones and untold other numbers of items.
But as noted, rarely was the production of war material sufficient to fully equip a division. Usually, a division would be issued roughly half the equipment its tables of organization called for. That limited allocation would at least allow the division to begin training.
But while a partial allocation might be enough to begin training, it was usually only sufficient to train at the individual and small team level. A division however, is more than a collection of small teams. It was a carefully designed tactical formation, a weapon that was more than the sum of its parts. It was designed to be wielded as an entire formation, and as such, it needed to train at all levels, from the individual up through and including the entire division. But putting the entire division through its paces was clearly impossible without its full complement of equipment.
Of course, the division’s Quartermasters would attempt to draw the rest of the division’s equipment as training went along. The hope was that by the time regimental and divisional level training took place, the full allocation of equipment would be on hand.
It rarely worked so smoothly. First, even as the Army was struggling to mobilize divisions, industry was still struggling to ramp up production of military equipment. Worse, just about the time the fruits of that production star
ted to come forth, Lend Lease came upon the scene, and much of what the Army had planned for was suddenly diverted to Britain, Russia, China, and other Allied nations.
Even as divisions trained on what little equipment they had, changes were afoot. New models of equipment or entirely new types were introduced into service, meaning that a division would have to completely retrain on new equipment. One example is the basic rifle of the Army. M1 Garand production was slower than hoped, so prior to 1943, virtually all the divisions created trained throughout their mobilization with the M1903A3 Springfield rifle. Only when they were alerted for embarkation for overseas service would they receive M1 rifles.
The production of equipment and the mobilization of divisions did not often align, and neither did the mobilization of divisions, and the need for divisions to deploy. Early deployment of US forces, particularly before our entry into the war in December 1941, were usually regimental sized and limited to the Western Hemisphere for the defense of advance bases in places such as the Caribbean. Early campaigns such as the invasion of North Africa in Operation Torch employed divisions that hadn’t fully completed their training. Worse, not having the full complement of their equipment, they were forced to strip other divisions in training of what little equipment they’d managed to gather. That had a knock on effect of delaying the training of those units. It would be well into 1943 before a division could reasonably expect to have a complete divisional set of equipment for the final phases of its training.
Simply keeping people in the division during training was a struggle. One of the key concepts of the Army in WWII was that we would field a small overall number of divisions, but they would be kept at full strength through individual replacements once committed to combat operations.
But even before deployment, indeed, throughout training, a division would face a drain on its manpower. The cadre that first formed the core of a division had come from another division, further along in the training pipeline. Eventually, our division in training would be tasked to calve off 1100 or so of its most experienced officers and men to form the cadre of yet another division. This large-scale turnover in often key personnel was often a significant blow to the training of a division. And it wasn’t the only drain on manpower. Throughout the Army, volunteers were sought for special programs, such as Airborne training, special units, transfers to the Air Corps, and large numbers of the brightest enlisted men to attend Officer’s Candidate School (OCS). New draftees would be sent to bring the division back up to strength during its training, but the need to train those draftees at the individual level while simultaneously trying to train the units at higher levels was a challenge. Turnover of a quarter of a division’s personnel was not uncommon, and as much as half in some cases.
We will describe the challenges of providing a post and associated facilities for raising and training a wartime division in a later post.
In spite of the challenges facing a division commander when tasked to raise a division for service in World War II, the Army, and LTG McNair’s Army Ground Forces had devised a well thought out program that did allow the Army to raise and train divisions rapidly. Some divisions were better trained than others when deployed, but that was often more a matter of the talents of the commanders than of the training program devised. The division making process was successful enough that of the five US divisions committed to the invasion of Normandy on D-Day, arguably the single most important day of the war, three had never before been in combat.