The 591st has a history dating back to WWII, serving in Northern France, Rhineland and the Ardennes-Alsace.  The Company was deactivated in Germany on March 14, 1947.  Then was again called to service prior to the Korean War and was deactivated once more on January 25, 1946.

The 591st was next activated July 1, 1966 at Fort Campbell, Kentucky.  As personnel and equipment arrived, the Company began the process of training for deployment to Vietnam and received orders for duty in the Republic of Vietnam on April 17, 1967.  All of the equipment was loaded and sent to Vietnam and the men were flown to California then departed by troopship to Vietnam.

Upon arriving in Vietnam the Company was attached to the 27th (Combat) Engineer Battalion, in the 79th Engineer Group, in direct support of the 11th Armored Cavalry Regiment at Blackhorse Basecamp.  The Company sent out platoons and individuals on support missions throughout the Four Corps Tactical Zones.  Building a rock crusher site, air strips, and providing maintenance for Highway 1.  The 591st was also one of the first Company's to provide equipment and personnel for the Rome Plow teams.

In April of 1968 the 591st and the 27th Eng. Battalion were transferred to the 18th Eng. Brigade, 45th Eng. Group and took up operations in I Corps tactical zone at Gia Le.  Working at Camp Eagle, Bastone, Phu Thu, Phu Bai, and constructing Rt 547 into the A Shau Valley in support of the 101st Airborne Division.  Once again building fire support bases, a quarry at Phu Loc, and a multitude of helicopter and artillery revetments.

The 591st was deactivated January 1, 1972.  Having served 5 years in Vietnam, while receiving 3 Meritorious Unit Commendations, in 1969, 1971 and 1972, and the Republic of Vietnam Civil Actions Honor Medal 1st Class.