USMC Organisation in WW2

USMC Infantry Company (1942-43)

  Headquarters

  3 Infantry Platoons

    Headquarters

    3 Squads
      1 x BAR
      8 x Bolt-action rifles or M1 Garand Rifles (1943)

  Heavy Weapons Platoon

    Headquarters

    2 Squads
      2 x .30 cal LMG

    1 Squad
      2 x 60mm Light Mortar

USMC Infantry Company (1944-45)

  Headquarters

  3 Platoons

    Headquarters

    3 Squads
      3 x BAR
      10 x Semi-auto Rifle

1st Marine Raider Battalion (1942-43)

  Headquarters Company [150 men]

    Battalion Headquarters [91 men]
      2 x .30 cal LMG
      4 x 60mm Light Mortar

    Communications Platoon [23 men]

    Quartermaster and Maintenance Platoon [36 men]
      5 x 1-Ton Truck
      2 x 2.5-Ton Truck

  Weapons Company [211 men]

    Company Headquarters [33 men]

    Demolitions Platoon [76 men]
      Demolition Charges

    Mortar Platoon [36 men]
      3 x 60mm Light Mortar

    2 Machinegun Platoons [33 men each]
      4 x .30 cal LMG

  4 Rifle Companies [135 men each]

    Company Headquarters [18 men]

    Weapons Platoon [30 men]
      2 x .30 cal LMG
      2 x 60mm Light Mortar

    3 Rifle Platoons [29 men each]

2nd Marine Raider Battalion (1942-43)

  Headquarters Company [150 men]

    Battalion Headquarters [91 men]
      2 x .30 cal LMG
      4 x 60mm Light Mortar

    Communications Platoon [23 men]

    Quartermaster and Maintenance Platoon [36 men]
      5 x 1-Ton Truck
      2 x 2.5-Ton Truck

  6 Rifle Companies [109 men each]

    Company Headquarters [18 men]

    Weapons Platoon [30 men]
      2 x .30 cal LMG
      2 x 60mm Light Mortar

    2 Rifle Platoons [29 men each]

Marine Parachute Battalion (1942)

  Headquarters Company [106 men]

    Battalion Headquarters [57 men]
      2 x Jeep
      1 x 1-Ton Truck
      3 x 2.5-Ton Truck

    Demolitions Platoon [34 men]
      Demolition Charges

    Company Headquarters [15 men]

    Pack Howitzer Platoon [unknown]
      4 x 75mm Pack Howitzer (estimated)

  3 Parachute Companies [159 men each]

    Company Headquarters [42 men]
      1 x Jeep

    3 Parachute Platoons [39 men each]

      Platoon Headquarters [4 men]
        1 x .30 cal LMG
        1 x Bazooka

      Mortar Squad [5 men]
        1 x 60mm Light Mortarj

      3 Parachute Squads [10 men each]