Initially a new experimental unit was formed, the 11th Air Assault Division, combining light infantry with integral helicopter transport and air support. Following training and testing, the unit was activated for Vietnam service with the designation 1st Air Cavalry Division, continuing the tradition of the 1st Cavalry Division.
The first unit of the new division to see action was the U.S. 7th Cavalry Regiment, led by Lieutenant Colonel Harold G. Moore, an old army paratrooper.
This was the same regiment that Custer had commanded at the Battle of the Little Bighorn. On November 14, 1965, he led his troops in the first large unit engagement of the 1960s Vietnam War, which took place near the Chu Pong massif near the Vietnam-Cambodia border. It is known today as the Battle of Ia Drang Valley.
This unit gave common currency to the US term
Air Cavalry.