The United States Marine Division, mid 1942 to mid 1943
Headquarters Battalion
Divisional Headquarters Company
Signal Company
Military Police Company
Special Weapons Battalion
Headquarters and Service Battery
Antiaircraft Artillery Battery - with sixteen towed 40-mm guns, divided into four Platoons with four guns per Platoon.
Three Antitank Batteries - each with six 37-mm antitank guns in three Platoons of two guns each, plus a fourth Platoon with two halftrack mounted 75-mm guns.
Three Marine Infantry Regiments, each comprised of;
Headquarters and Service Company
Weapons Company - with twelve 20-mm light antiaircraft guns in three Platoons of four guns each, plus a fourth Platoon with two halftrack mounted 75-mm guns (substitute equipment due to absence of 20-mm guns, 37-mm towed antitank gun or .50-cal heavy machine gun on same scale).
Three Marine Infantry Battalions - click on The United States Marine Battalion 1942 to early 1943 link for more detail.
Light Tank Battalion
Headquarters and Service Company
Four Light Tank Companies - each with eighteen light tanks.
Scout Company
Amphibian Tractor Company
Headquarters and Service Company
Three Amphibian Tractor Companies - each with thirty (?) tractors.
Divisional Artillery Regiment
Headquarters and Service Battery
Three Pack Battalions - each with twelve 75-mm pack howitzers, divided into three Batteries with four guns per Battery.
Howitzer Battalion - with twelve 105-mm howitzers, divided into three Batteries with four guns per Battery.
Divisional Engineer Regiment
Headquarters and Service Company
Engineer Battalion - with Headquarters Company and three Engineer Companies
Pioneer Battalion - with Headquarters Company and three Pioneer Companies
Naval Construction Battalion ('Seabees' assigned from US Navy)
Service Battalion
Headquarters Company
Service and Supply Company
Ordnance Company
Divisional Transport Company
Three Regimental Transport Companies
Medical Battalion
Headquarters and Service Company
Five Medical Companies
Points of note
Each Marine Division was also authorised a Marine Parachute Battalion, however these were slow to form and were quickly moved to Corps level.
The above 'D' Series organisation was markedly larger than its US Army counterpart, with organic Antiaircraft and Antitank units, its own Light Tank Battalion, and a specialised Amphibian Tractor Battalion which was initially used to ferry supplies from ship to shore. In other respects though it was light, with the 75-mm pack howitzer providing the bulk of the firepower of the Divisional Artillery Regiment.
The United States Marine Corps