Back home, the Grateful Dead was grooving a packed Fillmore West with "Turn on Your Love Light," while the Charlie guys were getting splattered with shrapnel.
They were just kids in the spring of 1969 when they were ordered to charge up Hill 484 in Vietnam.
The boys of Charlie Company, 1st Battalion, 4th Marines were 18 and 19 years old, following the lead of a 22-year-old.
They took Hill 484, and its neighbor, Hill 400, but at a cost of 15 or more casualties and at least seven killed in action.
Their valor earned a number of Navy Crosses, Silver Stars and Purple Hearts. One Marine received two Silver Stars, then spent 16 months in a hospital recuperating. Some of the medals were awarded posthumously. And a box full was forgotten altogether.
Cpl. Cleveland King Jr. was a radio man who earned a Silver Star, a Bronze Star with Valor and a Purple Heart with two gold stars. He never received them until March 31. He walked with a cane into a special ceremony in Huntsville, Ala.
It was also special because it brought 13 men of his 1st Platoon face to face for the first time in 43 years.
Douglas Jaquays of Lady's Island was one of them.
He describes an unleashing of emotion that for four decades was bottled up, put on a shelf, stuffed in the closet.
Now as grandfathers, the Charlie guys are back together. They're going to meet again next weekend. They want to do anything and everything for each other, just as they did on a hill that now, on Google Earth, looks overgrown and forgotten.
The band of brothers never forgot.
"We have a lot of friends whose names are on that wall," Jaquays said of the Vietnam War Memorial in Washington, D.C.
They felt that America shrugged when they got home from the stinking, rotten jungle where everyone was the enemy and Agent Orange filled the air.
Jaquays joined right out of Maple Heights High School in Cleveland.
On his first patrol, one of the men up front tripped a booby trap that blew off his foot.
"It's time to grow up," he told himself. "You've been sent here. You've got a job to do. You've got 13 months to go. Quit feeling sorry for yourself."
The guy they called "Jake" earned a Bronze Star and Purple Heart, was promoted to staff sergeant, served his four years, and went about his life.
"I didn't let it eat me up," he said.
He went to work for Sea Pines on Hilton Head, tending bar at the Quarterdeck. He was a manager at the Old Fort Pub, and lived in Hilton Head Plantation when there was no front gate and people hunted dove after the tomato and squash fields were disked in the fall.
He married Terry Boyd of Beaufort at the Old Fort Pub. She's the daughter of retired Marine Sgt. Maj. John Boyd and Mignon "Nanny" Boyd, and was in the last class of Tidal Waves at Beaufort High School.
Jaquays spent most of his career in construction. He and Terry raised two daughters, Aracely "Cely" Johnson, a teacher at Beaufort Elementary School, and Stephanie Harris of Beaufort.
Now 62, disabled and retired, Jaquays flies an American flag and Marine Corps flag in his front yard. He fit the trip to Alabama to see his "brothers" between radiation treatments for prostate cancer.
The march to the reunion started almost two years ago by a twist of fate.
Byron Moore, a state highway engineer in eastern North Carolina, was 2 years old when his father-in-law, Harold Wilson, stormed Hill 484.
"Me and my wife have been married for 15 years, and we'd been married six years before I knew her father was even in Vietnam or the Marine Corps," Moore said.
When that opened up, he started helping his father-in-law organize his photographs from Vietnam for the grandkids. He wanted to identify people in the photographs and piece together the stories. He turned to the Internet and email. He started with four or five names on an email list. Now it's almost 75 names, and he has scanned scores of photographs.
The group includes Karl Marlantes, a Yale University graduate and Rhodes Scholar who commanded the rifle platoon that included Jaquays and Wilson. Marlantes spent 35 years working on a novel that closely reflects their Vietnam experience. "Matterhorn: A Novel of the Vietnam War" came out in 2010 as a bestseller.
The group has brought together family members of boys killed on Hill 484 in 1969, and chopper pilots who risked their lives hauling out the casualties.
During the war, Wilson wrote a letter to the mother of a friend killed in Vietnam. He never heard back from her. Over the past two years, the veterans have been tracking the family. They finally found a sister of the slain Marine. She lives in North Carolina, within an hour of Wilson. When he reached her on the phone and started explaining the whole story, she said, "Harold, I'm holding the letter you wrote in my hands."
Moore said everyone he's contacted was glad to make old connections.
"I say I know I'm bringing up a lot of bad memories," Moore said, "but I hope it brings up a lot of good ones, too. I think in the back of their minds, they wanted to find closure."
Follow columnist David Lauderdale at twitter.com/ThatsLauderdale.