First Team
    Vietnam

The division went home in 1965, but only long enough to be reorganized and prepared for a new mission. Within 90 days of becoming the Army's first air mobile division, the First Team was back in combat as the first fully committed division of the Vietnam War. 

Their first real combat test came during the Pleiku campaign ; 35 days of continuous air mobile operations beginning October 29, 1965. The troopers destroyed two of the three regiments of a North Vietnamese Division, earning the first Presidential Unit Citation given to a division in Vietnam. 

The division began 1968 by terminating Operation Pershing, the longest of the 1st Cav's Vietnam actions. For nearly a year the division scoured the Bong Son plain, An Lo valley and the hills of coastal II Corps, seeking out enemy units and their sanctuaries. When the operation ended on January 21, the  enemy had lost 5,401 soldiers and 2,400 enemy soldiers had been detained. Some 1,300 individual  and 137 crew served weapons had been captured or destroyed. Moving to I Corps, Vietnam's northern most tactical zone, the division set up Camp Evans for their new base camp. In late January, the enemy launched the Tet Offensive, a major effort to overrun South Vietnam. Some 7,000 enemy, primarily well equipped, crack NVA regulars blasted their way into the imperial city of Hue and Quang Tri, the capital of Vietnam's northern most province. 

The Cav went on the move and by February 1, Quang Tri was liberated followed by Hue. After shattering the enemy's dreams of a Tet victory, the 1st Cavalry Division "Sky-troopers" moved to relieve the besieged Marine Base at Khe Sanh In May 1970, the First Team was "First into Cambodia," hitting what was previously a Communist sanctuary. Troopers deprived the enemy of much needed supplies and ammunition, scattering the 
 enemy forces. The division's Vietnam service ended in 1972 when its last brigade began withdrawing. The 1st Cav had been the first division to go, and the last to leave. 

"Firsts" had become the trademark of the First Team. General Creighton Abrams, while commander of  all U.S. Forces in Southeast Asia, said of the 1st Cav, "The big yellow patch does something to an  individual that makes him a better soldier, a better team member, and a better American than he  otherwise would have been." 

Information from:
http://www.grunts.net/army/1stcav.html