Battalion, 7th Cavalry, Task Force Garry Owen, remained another two months. In the Vietnam War, the division suffered more casualties than any other army division: 5,444 men killed in action and 26,592 wounded in action. However, the First Marine Division suffered 7,012 men killed in action and the Third Marine Division suffered 6,869 men killed in action. Air Cavalry troops This list of air cavalry troops is alphabetical by regiment, per the U.S. Army Combat Arms Regimental System, known as CARS, in use from 1957 to 1981. Under this system the unit nomenclature "regiment" was not used to designate the lineage of companies/batteries/troops or their parent battalions/squadrons. However, there were five armored cavalry regiments (ACRs) not organized under CARS, these units, including the 11th ACR, retained the "regiment" nomenclature in their official designation. Cold War service and REFORGER Exercise When the 1st Cavalry Division (Airmobile) departed Vietnam, its colors were retained by reflagging the existing 1st Armored Division at Fort Hood as the "new" 1st Cavalry Division, configured as an armored division. Concurrently, the colors of the 1st Armored Division were transferred to Germany where the 4th Armored Division was reflagged as the 1st Armored Division. In the aftermath of Vietnam, the 1st Cavalry Division was converted from an airmobile light infantry role into a triple capabilities (TRICAP) division. The unit received an infusion of mechanized infantry and artillery, to make it capable of missions needing three types of troops; armored, airmobility, and air cavalry. In the post-Vietnam era, morale in the US Army waned. In response, the Department of the Army released a morale–enhancing order in 1973 permitting local commanders to encourage morale-enhancing uniform distinctions. Consequently, many units embraced the wear of various military berets. The 1st Cavalry Division's use of various colored berets started in 1971 with the TRICAP experiment: black for armor, light–blue for infantry, red for artillery, and kelly–green for support. The division eventually settled on the use of black berets for all 1st Cavalry soldiers and continued wearing them until the Army's moral enhancing order ended in 1979. However, the TRICAP concept was short-lived, and by 1975, the division was reorganized under the Round-Out Division concept, with two active duty armored brigades and one National Guard armored brigade - the Mississippi Army National Guard's 155th Armored Brigade from 1984–1991. The division participated in numerous REFORGER exercises, and was used to test new doctrinal concepts and