Night had fallen as American and North Vietnamese soldiers exchanged sheets of gunfire during Operation Landing Zone X-Ray in the Ia Drang Valley in November 1965. Illumination flares attached to parachutes floated from American aircraft.

One parachute failed to open, and the flare plummeted into stacks of ammunition crates near the command post of the First Battalion, Seventh Cavalry Regiment, one of several American units engaged in the Vietnam War’s first major battle with North Vietnamese regulars.

Sgt. Maj. Basil L. Plumley jumped to his feet, reached into the pile, grabbed the burning flare and tossed it into a clearing. For that unhesitating action, he earned the Silver Star. It was one of more than 30 decorations he would receive; among the others were the rare honor of a Combat Infantryman’s Badge with two stars, signifying that he had fought in three wars.

“It’s very rare for someone to have served in World War II, Korea and Vietnam,” said retired Col. Greg Camp, executive vice president of the National Infantry Museum in Columbus, Ga., near Fort Benning. Only 325 soldiers have ever received what is known as the “Triple C.I.B.”