Oliver joined the U.S. Army's Airborne, and was assigned to the 506th Parachute Infantry Regiment, 101st Airborne Division. He dropped in to Normandy, on June 6, 1944, D-Day of Operation Overlord.
During the jump, his C-47 took heavy fire, and Oliver missed his Drop Zone at Vierville, and instead landed at Neuville. There, he broke his leg, and stayed with Captain Fred Hamill and his men whilst they looked after him.
On June 11, Captain John H. Miller and his men came, and asked where the rally point of Baker Company, 506th PIR was. He tells them where the rally point was for Baker Company, which was the company Private James Ryan was in.
His fate was left unknown.