E Troop, 1st Cavalry was first constituted March 2, 1833 as Company E, United States Regiment of Dragoons.
The unit has participated in the Mexican War, the Indian Wars, the Civil War, the War with Spain, World War II, and Vietnam.
On December 6, 1967, E Troop, 1st Cavalry, departed Hawaii aboard the USS General William Weigel for the Republic of Vietnam. The main body arrived at Quin Nhon on December 21, 1967. Immediately therafter, E Troop joined the 11th Infantry Brigade.
The unit's mission is to provide security and perform reconnaissance for the 11th Infantry Brigade and to engage in offensive, defensive, or delaying action as an economy of force unit.
In that same month, E Troop received nine M551 Armored Reconnaissance/Airborne Assault Vehicles, and since then E Troop has been employed as an armor unit and has been engaged primarily in security missions. Though somewhat limited in mobility by the terrain in the 11th Brigade's area of operation, E Troop has proved the value of armor-protected firepower on repeated occasions.
Source: the americal division, "under the southern cross" - published by the U.S. Army in 1971.
A 1969-1970 Yearbook was published for E Troop while the unit was in Vietnam and given to all the E Troopers serving at that time.