(1) Completion of Mobilization on WAR “K” series T/O, 12 August.
| 1st Marine Division, (Reinf) FMF | MajGen O. P. SMITH |
| HqBn, 1stMarDiv, less Brig Det | LtCol M. T. STARR |
| 1st SigBn, less Brig Det, 2 SP Comm Sects & Det Anglico Carrier Plat, FMF | Maj R. L. SCHREIER |
| 1st ServBn, less Brig Det | LtCol C. L. BANKS |
| 1st OrdBn, less Brig Det | Maj L. O. WILLIAMS |
| 1st MT Bn, less Cos A and D; 1st Amph Trk Co, FMF, less 1 Plat | LtCol O. L. BEALL |
| 1st Med Bn, less Cos A and E | Comdr H. B. JOHNSON, USN |
| 1st EngrBn, less Cos A and D | LtCol J. H. PARTRIDGE |
| 1st SP Bn, less Cos A and C | LtCol H. P. CROWE |
| 1st Tk Bn, less Cos A and D; Tk Plat AT Co, 1st Mar Tk Plat AT Co, 5th Mar | LtCol H. T. MILNE |
| 1st Amph Trac Bn, FMF, less Cos A and D | LtCol E. F. WANN |
| 1st Armd Amph Bn, FMF, less 1st Plat Co A and Cos C and D | LtCol F. H. COOPER |
| 1st CSG, SC, FMF, less BrigDet; 1st Fum & Bath Plat, SC, FMF 1st Aerial Del Plat, SC, FMF | Col J. S. COOK |
| 7th MT Bn, SC, FMF | Maj J. F. STEPKA |
| 1st Mar, less Tk Plat, AT Co; Cos C, F, and I, Reinf, 5th Mar | Col L. B. PULLER |
| 11th Mar, less 1st and 3rd Bns; Btry C, 1st 4.5″ Rkt Bn, FMF | Col J. H. BROWER |
(2) Organization for landing at INCHON, KOREA (1st Prov Mar Brig disbanded 13 September, units and detachments reverted control parent organizations of division). Task Organization from Annex “A”, 1st Mar Div Op Order 2-50 as derived from X Corps Op Order No. 1.
| 1st Marine Division (Reinf) FMF | MajGen O. P. SMITH |
| HqBn, Reinf, 1stMarDiv, less dets | |
| 163rd Mil Int Service Det | |
| 441st CIC Det | |
| 1st Sig Bn, Reinf, less dets; | |
| Det, 205th Sig Rep Co USA | |
| Carrier Plat, FMF | |
| Det, 4th Sig Bn, USA | |
| 1st Serv Bn, less Dets | |
| 1st MT Bn | |
| 1st Ord Bn, less dets | |
| Det, MTACS-2 | |
| Blt-3, RCT-5 | LtCol R. D. TAPLETT |
| 3dBn, 5th Mar | |
| Det, ANGLICO, 1st Sig Bn | |
| Det, Co A, 1st Tk Bn | |
| Recon Det, 11th Mar | |
| Team 1, SP Gp A | |
| 1stPlat, Co A, 1st SP Bn | |
| SP Comm Sqd, 1st Sig Bn | |
| Amm Sqd, 1st Ord Bn | |
| Det, Rat Sec, 1st Ser Bn | |
| Det, 1st CSG, (SP Aug) | |
| Det, Bchmstr Unit, USN | |
| RCT-5 | LtCol R. L. MURRAY |
| 5th Mar, less 3dBn & Tk Plat, AT Co | |
| Co A, 1st Engr Bn | |
| Co C, 1st Med Bn | |
| Det Anglico, 1st Sig Bn | |
| ROK Marine Bn | |
| SP GP A, less Team 1; | |
| Co, A, 1st SP Bn, less 1 Plat | |
| Evac Sec, 1st SP Bn | |
| Det, Ord Sup Plat, CSG | |
| Det, Auto Sup Plat, CSG | |
| Det, Engr Sup Plat, CSG | |
| Det, CS Plat, CSG | |
| Det, Sig Sup Plat, CSG | |
| SP Comm Sec, 1st Sig Bn | |
| Det, 1st CSG (SP Aug) | |
| Det, Bchmstr Unit, USN | |
| 1st Traffic Plat, MP Co | |
| Police Sqd, MP Co | |
| FO & Ln Sec, 1st Bn, 11th Mar | |
| Co A, 1st Tk Bn, less det | |
| Det, Sig Co, 1st Sig Bn | |
| RCT-1 | Col L. B. PULLER |
| 1st Mar, less Tk Plat, AT Co | |
| Co A, Reinf, 56th Amph Trac Bn, USA | |
| Btry C, 1st 4.5″ Rkt Bn, FMF | |
| Co C, Reinf, 1st Engr Bn, less det; | |
| Water Sup Sec | |
| Co D, 1st Med Bn, less det | |
| Det ANGLICO, 1st Sig Bn | |
| SP Gp B, less Team 3; | |
| Co B, 1st SP Bn, less 1 Plat & Equip Sec | |
| Evac Sec, 1st SP Bn | |
| Amm Plat, less 1 Sqd, 1st Ord Bn | |
| Rat Sec, 1st Ser Bn | |
| Fuel Sec, 1st Ser Bn | |
| SP Comm Sec, 1st Sig Bn | |
| Det, Bchmstr Unit, USN | |
| Det, 1st CSG (SP Aug) | |
| 2d Traffic Plat, MP Co | |
| Police Sqd, MP Co | |
| FO & Ln Secs, 2d Bn, 11th Mar | |
| 11th Mar, less 3d Bn, reinf | Col J. H. BROWER |
| 96th FA Bn, USA | |
| Det, Co B, 1st Engr Bn | |
| 1st Amph Trk Co, FMF | |
| 1st Tk Bn, less dets, reinf | LtCol H. T. MILNE |
| Tk Plat, AT Co, 1st Mar | |
| Tk Plat, AT Co, 5th Mar | |
| 1st Engr Bn, less dets | LtCol J. H. PARTRIDGE |
| 1st SP Bn, less dets | LtCol H. P. CROWE |
| H&S Co, 1st SP Bn, less dets | |
| SP Comm Sec, 1st Sig Bn | |
| Team 3, SP Gp B | |
| 3d Plat, Co B, 1st SP Bn | |
| Equip Sec, Co B, 1st SP Bn | |
| SP Comm Sec, 1st Sig Bn | |
| Det, Ord Sup Plat, CSG | |
| Det, Auto Sup Plat, CSG | |
| Det, Engr Sup Plat, CSG | |
| Det, Sig Sup Plat, CSG | |
| Det, GS Plat, CSG | |
| Det, Depot Plat, CSG | |
| Rcn Co, 1st MAR Div | Capt K. J. HOUGHTON |
| 1st Amph Trac Bn, FMF | LtCol E. F. WANN |
| VMO-6 | Maj V. J. GOTTSCHALK |
| ROK Marine Regt (-) | Col SHIN, KMC |
| 2d Engr Spec Brig reinf | Col J. TWITTY, USA |
| 1st CSG, SC, FMF, less dets | |
| 1st Fum & Bath Plat | |
| 1st Aerial Del Plat | |
| Naval Beach Gp 1, less dets | |
| 7th MT Bn, SC, FMF | |
| 73d Engr (C) Bn, USA | |
| 50th Engr Port Const Co, USA | |
| 65th Ord Amm Co, USA |
(3) RCT-7 Task Organization on landing at INCHON, KOREA, 21 September. Attachments reverted to parent control on arrival assembly areas.
| RCT-7 | Col H. L. LITZENBERG |
| 7th Mar | |
| 3d Bn, 11th Mar | |
| Co D, 1st MT Bn | |
| Co D, 1st Tk Bn | |
| Co D, 1st Engr Bn | |
| Co E, 1st Med Bn | |
| Co C, 1st SP Bn | |
| Det, 1st Sig Bn (ANGLICO & 2 SP Comm Sec) |
(4) Intermediate temporary attachments and detachments during the period 15 September-7 October.
18 Sept—32nd RCT USA attached 1st Mar Div
19 Sep—SpOpnsCo USA attchd 1st Mar Div
32nd RCT detached 1st MarDiv reverted to 7th Inf Div