[1] The Battalion served in the Pacific Theater during World War II, earning three campaign streamers for New Guinea, the Bismarck Archipelago, and Luzon.
The battalion was the first U.S. engineer battalion-size unit in Vietnam and responsible for port transportation and support facilities construction.
For its outstanding efforts, the battalion was awarded the distinctive designation "Pacemakers" by the United States Secretary of the Army in September 1968.
The battalion deployed elements from HSC, Alpha and Bravo Companies to McCall, Idaho in support of Task Force "Rugged-Pacemaker" to fight forest fires in the summer of 1994.
Meanwhile, HSC and elements of Bravo Company deployed to Hanford, Washington, with one day notice, to combat fires in that area.
In April 1997, Bravo Company deployed to Thailand in support of "COBRA GOLD" to provide humanitarian and civic assistance, in the form of new construction and facilities upgrade.
Shortly thereafter, in May 1999, Alpha company deployed to Thailand in support of "COBRA GOLD" to again provide humanitarian and civic assistance, in the form of new construction and facilities upgrade.
Meanwhile, Bravo and HSC were busy taking part in constructions missions that were vital to the Army's new Medium Brigade Transformation Project being conducted at Fort Lewis.
In March 2002, Alpha Company also deployed to Fallon, Nevada in order to build several training targets for the Naval air station located there.
The 864th redeployed to Fort Lewis on 27 March 2006 and then deployed yet again ten months later in February 2007 to Afghanistan in support of Operation Enduring Freedom VI, VII, and VIII.
The unit is composed of the following units: Constituted 14 December 1942 in the Army of the United States as the 864th Engineer Aviation Battalion Activated 1 January 1943 at Geiger Field, Washington Inactivated 30 June 1946 in Japan Allotted 18 February 1949 to the Organized Reserve Corps Activated 14 March 1949 at Morristown, New Jersey Inactivated 22 September 1949 at Morristown, New Jersey Activated 1 March 1951 at Tulsa, Oklahoma (Organized Reserve Corps redesignated 9 July 1952 as the Army Reserve) Inactivated 11 July 1952 at Tulsa, Oklahoma Withdrawn 8 July 1955 from the Army Reserve and allotted to the Regular Army Activated 25 September 1955 at Wolters Air Force Base, Texas Reorganized and redesignated 15 May 1956 as the 864th Engineer Battalion (Lettered companies inactivated 16 October 2008 at Fort Lewis, Washington; Support Company concurrently constituted and activated) 557th Engineer Company (Horizontal) inactivated 15 October 2014 in support of Army Structure Reorganization (Total Army Analysis 15-19) 28th Engineer Detachment(Concrete) inactivated 1 September 2015 due to 12V MOS leaving Active Duty and returning to Army Reserve and National Guard only New Guinea, Bismarck Archipelago, Luzon Defense, Counteroffensive, Counteroffensive Phase II, Counteroffensive Phase III, Tet Counteroffensive, Counteroffensive Phase IV, Counteroffensive Phase V, Counteroffensive Phase VI, Tet 69/Counteroffensive, Summer-Fall 1969, Winter-Spring 1970, Sanctuary Counteroffensive, Counteroffensive Phase VII, Defense of Saudi Arabia, Liberation and Defense of Kuwait, Cease-Fire Liberation of Iraq, Transition of Iraq, Iraqi Sovereignty Camp BondSteel Infrastructure and surrounding areas, A Company, in support of 1st Infantry Division August 1999 - February 2000 Consolidation I, Consolidation II, Consolidation III, Transition I This article incorporates public domain material from 864th Engineer Battalion Lineage and Honors.