Armoured cavalry

They began to replace horse cavalry in the heavy shock and the light reconnaissance, skirmishing and exploitation/pursuit roles in most armies commencing after the First World War.

Following mechanization, the few remaining distinctions of unit type became meaningless; cavalry regiments moved between the heavy and light armoured roles regardless of their names.

Unlike armoured and infantry units, U.S. Cavalry is organized into squadrons and troops, which are equivalent to battalions and companies respectively.

The three ground troops were a mixture of M48 Patton or M551 Sheridan tanks and M113 ACAVs (Armored Cavalry Assault Vehicles).

The aviation troop of the squadron was equipped with helicopters, consisting of UH-1 transports, OH-6 Cayuse scouts, OH-58 Kiowa scout/gunships, and AH-1 Cobra gunships.

During the Vietnam War, it was the mission of armour (tanks) to close with the enemy and defeat them using firepower, manoeuvre, and shock action.

In Vietnam, the US Army deployed 1 Armored Cavalry Regiment (containing 3 squadrons and an aviation squadron), 7 Armored Cavalry Squadrons, and 2 Armored Cavalry Troops: From about January 1969 until the last mounted unit re-deployed from Vietnam in 1972 (air units remained in country), most armoured cavalry units (except the 11th ACR's tank companies) were equipped with the M551 Sheridan armored airborne reconnaissance assault vehicle (today, known to historians as a light tank).