While attending the United States Military Academy at West Point, Carpenter played as a split end on the football team, alongside Heisman Trophy-winning halfback and fellow combat infantryman Pete Dawkins.

[6] In 1966, Captain Carpenter's C Company, 2/502nd Parachute Infantry of the 101st Airborne Division took part in Operation Hawthorne, fighting North Vietnamese forces near Dak To on the Kontum plateau in the Central Highlands.

As the situation grew desperate, Carpenter radioed the battalion air traffic controller for a napalm airstrike on his own position: "We're overrun, they're right in among us.

For his actions, he was again awarded the Silver Star, which was later upgraded to the U.S. Army's second highest wartime medal, the Distinguished Service Cross[8] and earned the nickname, "Napalm Bill" Carpenter.

[8] Carpenter committed another act of heroism on February 1, 1967, at Tan Son Nhut Air Base in Saigon when he carried an injured man to safety after a plane crash landed.

After a C-123 Provider military transport aircraft made a belly landing on the runway, Captain Carpenter "hoisted the injured man onto his shoulders and scampered from the gasoline-soaked plane.