Bazooka Team, France 1944
Bazooka Team France 1944
bigpigeon.us webpage WWII US > Ground Forces > Infantry Organization, © 2023 by Robert A. Christiansen, updated by RAC 11 Jan 2023.
​The organizational structure for WWII US Army infantry units, from largest to smallest, was
​    division > regiment > battalion > company > platoon > squad.
Links to Big Pigeon's Infantry Division Organization webpages:
➨➨​ WWII US Army Infantry Division Organization 
Along with an headquarters company and some components smaller than a company in size, each WWII Army infantry division contained the organic (i.e., permanent) units shown on the accompanying chart:
  • three infantry regiments.
  • division artillery with four field artillery battalions.
  • an engineer combat battalion.
  • a medical battalion.
  • a company-sized reconnaissance troop.
  • one each of a signal, ordnance, and quartermaster company.
​These organic units were each identified by a number; e.g., 168th Infantry Regiment of the 34th Infantry Division is of special interest to me.
WWII US Infantry Division
WWII US Army Infantry Division Organizational Chart
Note that a WWII US Army infantry division included units from the following US Army branches besides the Infantry:
  • Field Artillery
  • Corps of Engineers
  • Cavalry Corps - abolished after WWII
  • Signal Corps
  • Ordnance Corps
  • Quartermaster Corps
  • Military Police Corps
  • Medical Corps
Aside from the Medical Corps and forward artillery observers, infantry units within a division did not usually contain members of the above corps.
➨ Within a WWII US Infantry Division, an Infantry Regiment
WWII Army and Marine Corps infantry regiments had a similar organization.  Each regiment had three battalions, and each battalion had four companies:
  • 1st Battalion: Co. A (rifle), Co. B (rifle), Co. C (rifle), Co. D (heavy weapons)
  • 2nd Battalion: Co. E (rifle), Co. F (rifle), Co. G (rifle), Co. H (heavy weapons)
  • 3rd Battalion: Co. I (rifle), Co. K (rifle), Co. L (rifle), Co. M (heavy weapons)

​Note how a company is identified by a letter. If you know the company letter you can identify the battalion.
TO&E Outline for a WWII Infantry Regiment
WWII US Infantry Regiment, Organizational Chart
➨ Within a WWII US Army Infantry Division - the Divisional Artillery
In 20th century wars, artillery fire caused more casualties than small arms fire. 

Supporting this fact, the US Army deployed massive amounts of artillery in WWII. Each infantry division contained four artillery battalions, with additional battalions held in corps and army reserve.

Note from the accompanying graphic that WWII divisional artillery, known as divarty, was authorized to have 36 105mm howitzers and 12 155mm howitzers. During WWII most artillery, except in armored artillery battalions, was towed rather than self-propelled. ​
WWII US Army Infantry Division, Divisional Artillery
WWII US Army Infantry Divisional Artillery, Organizational Chart
US Army Infantry division artillery:
  • Three battalions of 105-mm howitzers and one of 155-mm howitzers. 
  • In addition, each infantry regiment had a 105-mm howitzer cannon company and a 57-mm gun antitank company.
US Marine Corps division artillery:
  • Four or five artillery battalions, organized into a 4th regiment; e.g., the 22nd Marine Regiment (artillery) was the 4th regiment in the 1st Marine Division.
  • Early in WWII, a marine division’s artillery regiment had three battalions of 75-mm pack howitzers and one of 105-mm howitzers.
  • As the war progressed, more 105-mm howitzers were added and the number of pack howitzers was reduced.
Divisional artillery for other division types.
Army Light Armored division:
  • Three battalions of self-propelled 105-mm howitzers mounted on the M7 Priest motor carriage.
Army Airborne division:
​WWII US Infantry Division, Commentary:
​
An ETO focus group after WWII ended indicated strong support for augmenting an infantry division thusly:
  • Increase the Engineer Corps battalion to a two-battalion regiment.
  • The current Cavalry Reconnaissance Troop is inadequate; no consensus on changes.
  • Add more trucks to the Quartermaster Corps component.
  • Add organic armored units of a battalion or more. In the ETO, a tank or anti-tank battalion had almost always been attached to an infantry division.
  • Add an organic anti-aircraft battalion. (RAC smaller anti-aircraft weapons could also be successfully used against ground target, as the Wehrmacht had demonstrated).
➨➨​ WWII US Army Infantry Regiment Organization 
In 1941, the US Army had converted infantry divisions from rectangular (four infantry regiments) to triangular (three infantry regiments).
​
As noted earlier, each WWII infantry regiment had three infantry battalions, and each infantry battalion had three rifle companies and a heavy weapons company, identified thusly: 
  • 1st Battalion: Co. A (rifle), Co. B (rifle), Co. C (rifle), Co. D (heavy weapons)
  • 2nd Battalion: Co. E (rifle), Co. F (rifle), Co. G (rifle), Co. H (heavy weapons)
  • 3rd Battalion: Co. I (rifle), Co. K (rifle), Co. L (rifle), Co. M (heavy weapons)

The accompanying diagram depicts an infantry regiment late in WWII. Changes from early WWII include:
  • Adding 2.36 inch antitank rocket launchers, known as bazookas.
  • Upgrading antitank guns from 37mm to 57mm.
WWII US Infantry Regiment
WWII US Army Infantry Regiment Organizational Chart
➨ Within a WWII US Army Infantry Regiment, an Infantry Battalion
Aside from battalion headquarters components, a WWII infantry battalion consisted of three rifle companies and a heavy weapons company.
WWII US Infantry Battalion
WWII US Army Infantry Battalion T/O&E Outline
T/O&E = Tables of Organization and Equipment
➨ Within a WWII US Army Infantry Regiment - the Anti-Tank and Cannon Companies
During the latter years of WWII, each US infantry regiment included the following two companies:
  • An anti-tank company, equipped with six 57mm guns. These guns were not effective against heavy tanks, but were an improvement over the 37mm guns used by anti-tank companies earlier in the war.
  • A cannon company, equipped with six 105mm M3 howitzers. These were a lighter version of the 105mm M2 howitzers used by field artillery units.
WWII US Infantry Anti- Company
WWII US Army Infantry Anti-Tank Company
WWII US Cannon Company
WWII US Army Infantry Cannon Company
➨➨​ ​WWII US Army Infantry Battalion Organization
Aside from battalion headquarters components, a WWII infantry battalion consisted of three rifle companies and a heavy weapons company.

A rifle company had three rifle platoons.
The infantry battalion's heavy weapons company included .30 caliber water-cooled machine guns and 81mm mortars.

Early in 1943, an anti-tank rocket known as the 2.36 inch Bazooka, was introduced.
  • On some charts herein, Bazookas are called ATRLs, anti-tank rocket launchers.
  • ​Bazooka use required a two-person gunner-loader team, who ordinarily had other duties.
  • It appears that an infantry battalion held about 14 bazookas, distributed between the headquarters company and the heavy weapons company.
WWII US Infantry Battalion
WWII US Army Infantry Battalion Organizational Chart
➨ Within a WWII US Army Infantry Battalion - a Rifle Company
About the accompanying visual:
  • Until the middle of 1945, a rifle company's authorized strength was always under 200, not 250 as the visual suggests, and a rifle squad's authorized strength was 12.
  • Arty FO denotes field artillery forward observer, attached from one of the division's field artillery battalions .
  • A rifle company would also have attached several medics from the division's medical battalion. 
WWII US Army Rifle Company
WWII US Army Rifle Company Organization
➨ Within a WWII US Army Infantry Battalion - the Heavy Weapons Company
I have not found a suitable organizational chart for a WWII US Army infantry heavy weapons company to include here.

The accompanying textual description is courtesy of ​https://en.wikipedia.org/wiki/Weapons_company.
​In February 1944, a full-strength US Army infantry heavy weapons company had 160 men in total, organized into a company headquarters, two machine gun platoons and a mortar platoon.
  • The 28-man company HQ held a single .50 caliber M2 Browning heavy machine gun.
  • Each 36-man machine gun platoon consisted of a six-man HQ and two 15-man machine gun sections, each with two .30 caliber M1919 Browning machine guns, for a total of eight .30 caliber machine guns. 
  • The 60-man mortar platoon consisted of a six-man HQ and three 18-man mortar sections, each with two 81mm M1 mortars, for a total of six mortars.
  • Each of the three platoon HQs also held two Bazooka rocket launchers each, for a total of six Bazookas.
➨➨​ ​​WWII US Army Infantry Regiment Rifle Company and Rifle ​Platoon Organization
Aside from company headquarters components, a WWII US rifle company consisted of  three rifle platoons and one weapons platoon.
  • A rifle platoon had three rifle squads.
  • A rifle company weapons platoon included two .30 caliber air-cooled machine guns and three 60mm mortars.

As for motorized equipment, each rifle company, of about 193 men at full strength, was authorized only two jeeps!
WWII Rifle Company Organization
WWII US Army Rifle Company Organizational Chart
Company Headquarters
Company Headquarters
OF = officer, OR = Other Ranks
Rifle Platoon Organization
Rifle Platoon Organization
Weapons Platoon Organization
Weapons Platoon Organization
➨➨ WWII US Army Rifle Squad Organization
The following weapons appear in the accompanying diagram, which depicts the complement of a full-strength 12-man army infantry squad early in WWII:
  • M1 Garand rifle.
  • M1918A2 Browning automatic rifle, known as the BAR.
  • M1903 Springfield rifle with a M1 grenade launcher.
Click on the thumbnails below to see each of these.
GI with M1 Rifle
GI with M1 Garand, the ETO
Marine with BAR
Marine with BAR, the Pacific
GI with M1903 Rifle and Grenade Launcher
GI with M1903 Springfield Grenade Launcher and Anti-tank Grenade
WW II Rifle Squad
WWII US Army Rifle Squad
About WWII US Army rifles:
  • The M1 Garand, introduced beginning in late 1937, was the standard weapon carried by most WWII rifleman. It was a semiautomatic rifle with an eight-round clip. At 43.5 inches in length, it weighted 9.5 pounds.
  • Infantry squads generally included a heavier M1918A2, the BAR, Browning Automatic Rifle. At 47 inches in weight, it weighted 19.4 pounds and held a 20-round magazine.
  • A platoon sniper and squad rifle grenadiers generally carried a M1903 Springfield rifle.
All the above used a 30.06 (7.62x63mm) cartridge, which the Browning M1917 water-cooled and M1919 air-cooled machine guns used.

The lighter, shorter US carbines of WWII eventually came in two flavors:
  • M1, introduced 1942, semiautomatic, 35.6 inches in length and 5.2 pounds unloaded, generally used a 15-round magazine.
  • M2, introduced October 1944, same specifications but with a fully-automatic mode, not widely used in WWII, generally used a 30-round banana magazine.
These carbines used the less-powerful 30.06 (7.62x33mm) rimless carbine cartridge.
Sources for Big Pigeon's WWII US > Ground Forces > Infantry Division Organization webpage:
General Sources: ​Sources for webpages images: The following two items are c/o Custermen - Dedicated to the Men of the 85th "Custer" Infantry Division, https://www.custermen.com, a website with much useful content.