1st Squadron, 4th Cavalry (1-4 Cavalry, popularly called "Quarterhorse") was assigned to be the divisional reconnaissance squadron of the 1st Infantry Division based at Di An. It arrived at Vung Tau on 7 October 1965, making it the first element of the 4th Cavalry to deploy to Vietnam. Commanded by LTC Paul M. Fisher, the Squadron was ready for action. On 12 November 1965, 1-4 Cavalry received its baptism by fire in the Vietnam War when Troop A, attached to 2-2 Infantry, engaged a VC regiment in the village of Bau Bang. Three enemy probing attacks were thrown back, and on the fourth charge, .50 caliber machine-gun fire broke up their assault and the enemy retreated, leaving 146 dead. On 24 February 1966, Troop B fought a stiff skirmish with the VC and repulsed the enemy. In April 1966, LTC Fisher became the executive officer of the 1st Brigade, 1st Infantry Division, and his replacement was LTC Leonard L. Lewane. LTC Lewane led the squadron in several operations in conjunction with other elements of the 1st Infantry Division, including Operations Birmingham El Paso and Shenandoah.