Many officers and men who participated in this campaign have contributed to the preparation of the book by answering inquiries, submitting to interviews, and commenting on the preliminary manuscript. Their assistance has been invaluable. Special acknowledgment is also extended to the Office of the Chief of Military History, Department of the Army, Pacific Section, and particularly Lieutenant Colonel Roy E. Appleman, USA, for enemy intelligence material; to the Marine Corps Board Study: _An Evaluation of the Influence of Marine Corps Forces on the Course of the Korean War_ for its interpretations and conclusions; and to _Life Magazine_ for courtesy shown in permitting use of Korean photographs made by Mr. David D. Duncan. Maps included herein were prepared by the Reproduction Section, Marine Corps Schools, Quantico, Va. United States Army, Navy and Marine Corps photographs have also been used to illustrate this monograph. [Illustration: (Signature)] T. A. WORNHAM, _Brigadier General, U. S. Marine Corps_. _Assistant Chief of Staff, G-3._ Contents _Page_ I Korea, Doorstep of Strategy 1 The Korean Question--The Russo-Japanese War--Korea as a Japanese Colony--The Partition of Korea--Red Victory in China--Civil Strife in Korea II Red Aggression in Korea 19 Units of the NKPA--NKPA Command and Leadership--The NKPA Infantry Division--NKPA Air and Armor--NKPA Officer Procurement Conscription--The NKPA Order of Battle III The Marine Brigade 37 NKPA Gains of First Week--Early U. S. Decisions--Geography of Korea--U. S. Ground Forces in Korea--Requests for U. S. Marines--Activation of the Brigade IV The Advance Party 55 Conference with CINCFE--The Washington Scene--The Advance Party in Japan--Voyage of the Brigade--The Advance Party in Korea--Crisis of the Eighth Army V Prelude to Battle 87 Reconnaissance by Jeep--Brigade Air Lands--Landing of Ground Force--Bedlam on Pusan Water Front--The Brigade at Changwon--The Pusan Perimeter--Brigade Air Strikes First--Planning the Sachon-Chinju Offensive VI Action on Hill 342 103 First Platoon Fight--The Perimeter on Hill 342--Call for Artillery Fires--Task Force Kean Stalled--General Craig Assumes Control--Enemy Attack at Dawn