Terry de la Mesa Allen, Jr.

Terry de la Mesa Allen, Jr. (1929–1967), son of Terry de la Mesa Allen, Sr., was a fourth generation soldier. He achieved the rank of Lieutenant Colonel. He served with the 1st Infantry Division, which his father had commanded in World War II. He was killed in an ambush in South Vietnam on 17 October 1967, while leading a battalion against the Viet Cong near Lai Khe, northwest of Saigon at the Battle of Ong Thanh. An account of that battle is detailed in They Marched into Sunlight, a book by David Maraniss. Allen was married to Jean Ponder of El Paso and had 3 children; Mary, Consuelo, and Alice.

Under steady pressure from higher-ups to forcefully engage the enemy, Allen, in what has been called an "ill-advised action", took two rifle companies, "A" and "D" on an attempt to contact hostle Viet Cong forces. These two rifle companies ran into an ambush by two much larger Viet Cong battalions that lay in wait along the trail. The Viet Cong forces allowed the lead company, Bravo to walk past the second of two battalions lying alongside the road as close as 10 meters away. Bravo Company continued up the trail and walked along the 1st of the two battalions which opened fire on the Bravo killing or wounding the entire force including LtCol Allen. After all but eliminating Alpha Company, the Viet Cong 2d battalion assaulted Company D, killing or wounding many of the remaining Americans.