Activated 17 Sept. 1944. Tasked with the overall control and supply of all Marine Corps assets in theatre.
When FMFPAC was activated, four units were assigned. The 1st through the 4th Service and Supply Battalions and eight depots. The bulk of supply operations in the pacific was accomplished by black labor troops organized into depot and ammo companies. A total of 12 ammo companies were raised. 51 Depot companies were raised. Every one of these units directly contributed to the combat effort by providing labor to load and unload tons of material to support Marines in the pacific. These units established a favorable reputation for black Marines by "...setting a high standard of discipline and combat effectiveness..." which led to an eventual integration of black Marines into desegregated units by the time of the Korean conflict.
With attached Navy SeaBee units these Battalions provided construction support in the pacific, notably Iwo Jima, and occupied China and Japan.
At the time of activation, five 155mm Howitzer Battalions, six 155mm Gun Battalions with each Division authorized four battalions of Artillery were active in the theater. FMFPAC Artillery units provided fire support in every major land operation in the pacific.
At the time of activation 16 AA Battalions were active in the pacific.
At the time of activation 6 companies were active. All saw action in the pacific providing support moving personnel, equipment and supplies from ship to shore.
At the time of activation there were two companies of 85 officers and men each assigned, with the first company supporting IIIAC and the second company supporting VAC. Each was organized into small highly mobile platoons. Missioned with clearing mine fields or unexploded ordnance which impeded the Marine Corps assault troops forward drive.
With 12 Amphibian Battalions in action at the time of activation, these units had seen action since the landing at Guadalcanal. See Gallery Section, Amphibious Tractors.
Six platoons were raised with 5 to FMFPAC and on with the 5th Division on Okinawa. The first use of the "War Dog Platoon" was with the 2nd Raider Regiment for the Bougainville operation. Most war dogs were German Shepherds, Belgian Sheep dogs or Doberman Pinschers. Both men and dogs were trained at Fort Washington MD., Fort Robinson NB., and Marine Barracks, New River NC, with a training period of about 14 weeks. War dogs served as messengers, scouts and night sentry duty.