1965 - 1972

In August 1965 the 1st and 2nd Battalions, 7th Cavalry sailed for South Vietnam. By this time, they had completed their initial training and were full-fledged air assault infantry battalions. Upon reaching Vietnam in September 1965, the 1st Cavalry Division began the construction of a massive firebase in the Central Highlands region of the Republic of Vietnam. In November 1965, the National Liberation Front (Viet Cong) attacked the Special Forces camp at Plei Mei. The division moved into the area, with the intent of trapping the Viet Cong forces between Plei Mei and the Laotian border. 1-7 landed in Landing Zone X-Ray, a small open field in the Ia Drang valley, to search for and destroy units on 14 November 1965. They landed in an area with nearly three full-strength regiments of the North Vietnamese Army and into what would become the first major battle of the Vietnam War. 1-7's battalion commander, LTC Harold G. Moore, had planned for a possible piecemeal engagement before all of his elements closed on LZ X-Ray, but they were nearly overwhelmed by the superior numbers of the NVA. Eventually 1-7, with elements of 2-7 were able to bring massive air, artillery, and aerial rocket artillery (helicopter) fires into the area. Once the codeword "Broken Arrow" was given, it meant that a US unit was in danger of being overrun and, upon acknowledgment, meant that the calling unit had priority of all aircraft in country. 1-7 and 2-7 had aircraft stacked at thousand foot intervals from 5000 to 30,000 feet waiting to drop ordnance.

Tactical air support was not the only air asset in the Ia Drang that day. For the first time, B-52 Stratofortress strategic bombers flew in direct support of a ground unit. One of the lasting concepts from the Ia Drang battle was that of the "Mad Minute," where for one minute every weapons system in the battalion would fire into the bush. These uses of overwhelming firepower and the intelligent deployment of ground units (to include units that arrived during the battle) allowed LTC Moore to save his command and destroy the 66th NVA Regiment (and also maul the 33rd and 320th NVA Regiments). This, the first battle between US and NVA ground forces, was a tremendous tactical victory, and validated the concept of airmobile infantry under the most rigorous battlefield conditions.

1-7, 2-7, and later, the newly-created 5-7 served in the 1st Cavalry Division through the war until 1972, and near the end, with all three battalions of the 7th Cavalry in 3rd Brigade, 1st Cavalry Division, the brigade picked up the nickname "Garryowen Brigade." 1st Battalion, 7th Cavalry inactivated at Fort Hood on 22 October 1972. Almost immediately afterwards, the division became the experimental test bed for the TRICAP, or "triple capability" division, consisting of one armored brigade, one light infantry brigade, and one aviation brigade. 1st Battalion (Armor), 7th Cavalry activated as an M60A1 tank battalion on 20 June 1974, and was part of the 2nd Brigade, 1st Cavalry Division until 1986. In 1985, 1-7 Cav traded in its M60s for M1IP tanks.

In 1986, the US Army Center of Military History made some realignments under CARS, and one of the changes that occurred was the redesignation of the division cavalry squadron from 1-9 Cav to 1-7 Cav. At that time, 1st Battalion, 7th Cavalry furled its colors and assumed a new identity as 3rd Battalion, 32nd Armor. At the same time, 1st Squadron (Recon), 9th Cavalry ceased to exist and became 1st Squadron, 7th Cavalry. According to Donna Everett, the curator for Armor and Cavalry lineages and honors at the Center of Military History, the specific reasons for making 1-7 Cav the division cavalry squadron was not known, but it was in response to a specific request by an unnamed general officer.