864th Engineer Battalion (United States)

864th Engineer Battalion
864th Engineer Battalion Distinctive Unit Insignia
Active	February 1942 – Present
Country	United States of America
Allegiance	Federal
Branch	Regular Army
Type	Battalion
Role	Engineer Battalion
Nickname(s)	"Pacemakers"
Motto(s)	"ALIQUID EXPECTAVIT(Anything Expected)"
Commanders
Current commander	LTC Jonathan J. Johnston

The 864th Engineer Battalion is a combat engineer battalion of the United States Army based at Joint Base Lewis-McChord, Washington. The battalion is a subordinate unit of 555th Engineer Brigade.

The 864th Aviation Battalion was activated in December 1942 at Camp Geiger, Washington near Spokane. The Battalion served in the Pacific Theater during World War II, earning three campaign streamers for New Guinea, the Bismarck Archipelago, and Luzon. The unit also earned the Philippine Presidential Unit Citation. The unit was deactivated in Japan on 30 June 1946. The army allotted the battalion to the organized Reserves and activated it at Morristown, New Jersey on 14 March 1949.

The unit was deactivated the following September. In March 1951, the Army reactivated the battalion at Tulsa, Oklahoma, only to inactivate it a year later. In 1955 the battalion was withdrawn from the Army Reserve and allotted to the Regular Army. The 864th was reactivated at Wolters Air Force Base, Texas on 25 September 1955. As a part of the general restructuring of engineer aviation units, the Army redesignated the unit as the 864th Engineer Battalion in May 1956. In May 1965, the battalion was shipped to Cam Ranh Bay, South Vietnam.

The battalion was the first U.S. engineer battalion-size unit in Vietnam and responsible for port transportation and support facilities construction. As more engineer battalions were assigned to Vietnam, the unit was assigned missions of base camp construction and line of communication construction and maintenance. 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 returned to the Contiguous United States in August 1971, after earning thirteen campaign streamers, the Vietnamese Civic Action Honor Medal, First Class, and two Meritorious Unit Commendations. In the Contiguous United States, the battalion was assigned to Fort Lewis, Washington.