This is the third volume in an operational and chronological series covering the Marine Corps’ participation in the Vietnam War. This particular volume details the continued build-up in 1966 of the III Marine Amphibious Force in South Vietnam’s northernmost corps area, I Corps, and the accelerated tempo of fighting during the year—the result being an “expanding war.” Although written from the perspective of III MAF and the ground war in I Corps, the volume treats the activities of Marine advisors to the South Vietnamese Armed Forces, the Seventh Fleet Special Landing Force, and Marines on the staff of the U.S. Military Assistance Command, Vietnam, in Saigon. There are separate chapters on Marine air, artillery, and logistics. An attempt has been made to place the Marine role in relation to the overall effort.

This is the second volume in a series of chronological histories prepared by the Marine Corps History and Museums Division to cover the entire span of Marine Corps involvement in the Vietnam War. This volume details the Marine activities during 1965, the year the war escalated and major American combat units were committed to the conflict. The narrative traces the landing of the nearly 5,000-man 9th Marine Expeditionary Brigade and its transformation into the ΙII Marine Amphibious Force, which by the end of the year contained over 38,000 Marines. During this period, the Marines established three enclaves in South Vietnam’s northernmost corps area, I Corps, and their mission expanded from defense of the Da Nang Airbase to a balanced strategy involving base defense, offensive operations, and pacification. This volume continues to treat the activities of Marine advisors to the South Vietnamese armed forces but in less detail than its predecessor volume, U.S. Marines in Vietnam, 1954-1964; The Advisory and Combat Assistance Era.

This is the third volume in a planned 10-volume operational and chronological series covering the Marine Corps' participation in the Vietnam War. A separate topical series will complement the operational histories. This particular volume details the continue d buildup in 1966 of the III Marine Amphibious Force in South Vietnam's northernmost corps area, I Corps, and the accelerated tempo of fighting during the year . The result was an "expanding war." The III Marine Amphibious Force had established three enclaves in I Corps during 1965. Employing what they believed was a balanced strategy—base defense, offensive operations, and pacification—the Marines planned to consolidate their base areas in 1966. At the beginning of 1966, the 1st Marine Division reinforced the 3d Marine Division and 1st Marine Aircraft Wing in Vietnam. By the end of the year, the III Marine Amphibious Force had nearly doubled in size. Two separate events, however, were to dash the high hopes held by the Marines in 1966. An internal political crisis in the spring halted the Marine pacification campaign south of the large Da Nang Airbase. In July, the North Vietnamese Army launched an incursion through the Demilitarized Zone and Marines went north to counter the enemy thrust. By December 1966, Marine units were stretched thin along the 265-mile length of I Corps. As one Marine commander observed, "too much real estate—do not have enough men." Although written from the perspective of III MAF and the ground war in I Corps, the volume treats the activities of Marine advisors to the South Vietnamese Armed Forces, the Seventh Fleet Special Landing Force, and Marines on the staff of the U .S. Military Assistance Command, Vietnam, in Saigon.

This book was donated as a part of the David H. Hugel Collection, an archival collection of the Special Collections & Archives, University of Baltimore.