Arlington Cemetary's Tomb of the Unknown Soldier in Arlington, Virginia, is a marble sarcophagus placed above the grave of the Unknown Soldier of World War I.

Inscribed on the back are these hallowed words: "Here rests in honored glory an American soldier known but to God."

To the west of the tomb are the crypts of unknown soldiers from World War II, Korea, and Vietnam.

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To serve as a tomb sentinel is a unique military honor. The soldier "walking the mat" does not wear rank insignia, so as not to outrank the Unknowns, whatever their ranks may have been. Tomb sentinels from the Army's 3rd Infantry Regiment's "The Old Guard" have guarded the tomb for 24 hours a day, 365 days a year — regardless of the weather — since 1948.

LifeZette spoke to two former tomb sentinels about their life-changing experience guarding the memory of America's unknown fallen, who gave their lives for our country's safety, honor, and freedom.

Sgt. Bill McCarley of Mission Viejo, California, Served at the Tomb of the Unknown Soldier from 1959 to 1960
"I have a fondness for that place. I always will," said McCarley of his time serving in the army in Washington, D.C. "I was a college dropout when I got there. In 1958 I wanted to play football for UCLA and I was told to lift weights and go to junior college for a year. Then I got injured, so some friends and I figured we wanted to travel and see the world. We decided to join the army."

McCarley completed his basic training at Fort Myer in Monterey, California. "I was interviewed and asked what I wanted to do — I had done fairly well on all the army tests," he said. "I told the staffer that I really wanted to go to Europe. That fellow said to me, 'You don't want to go to Europe because you have to be in the infantry, or in artillery.' I said, 'How do I get there the fastest?' He said, 'Infantry training — but nobody joins the infantry.'"

"So I said, 'Put me down for that,'" McCarley remembers, laughing. "I was a little crazy, a little wild back then."

About two-thirds of the way through his infantry training, McCarley was called to the orderly room at camp. "This soldier was there in this beautiful blue uniform, going around the country looking for candidates for the honor guard. I had been recommended by a sergeant or someone, so I said, 'Put me down for that, too.'"

McCarley was both a sentinel and a relief commander at the Tomb of the Unknowns. He was just 19 when he served at the tomb. "Fortunately, I was raised by a very disciplined father, so I didn't mind all the discipline of service. It was a magical time — I got to see many world leaders. The fellows I served with were just terrific. I was in with guys who were older, and they took me under their wing. All but one of them is gone now."

He remembers well the demands of tomb service. "It's very demanding physically, and you have to concentrate all the time," he said. "But you get into a groove. And you are timed, and checked on frequently during your time on the mat. They change the guard more frequently now. When I was there you walked for one hour, and were off for three, during a 24-hour shift."

McCarley served his duty at a tumultuous time in U.S. history, right after the Korean War and before Vietnam.

"One of the things that always touched me, as I was changing the guard, was when people came up to me. Some who lost loved ones overseas would say, 'Thank you for watching over my son.' Perhaps they'd never gotten the bodies of their loved ones back."

McCarley recalls performing ceremonial duties at the White House when dignitaries would visit. "I opened the door for Jackie Kennedy," he remembered. "She was very striking."

He also met a power player on the world's political stage. "[Nikita] Khrushchev came to the White House in 1960, and that was very sobering — we were in the Cold War," he said. "Eisenhower was president. I remember Khrushchev looked like a very healthy Iowa corn farmer, and Eisenhower was in very poor health. That was a powerful contrast."

McCarley remembers when his parents came to visit and to see him "walk the mat." "They were very proud. They showed up on the plaza while I was walking, and of course you can't acknowledge anyone, and so I walked back in forth in front of them as they looked on. My mother was a petite woman, and in those days people got dressed up to go places. I came off the mat, cleared my weapon, and was walking downstairs to the catacombs — you were considered off-duty once you got to the bottom of those stairs. As I walked, I heard this 'click-clack, click-clack,' and I knew it was my mother, chasing me down."

He continued, "When I got to the walkway I removed my sunglasses, and said, 'It's a heck of a way to make a living, huh, Mom?'"

His mother was unnerved by the sight of her son so solemn, walking the mat. "My mother said to me, in a little worried voice, 'Oh, I thought you forgot how to smile.'"

McCarley had a long and successful career after the military. He attended both California Polytechnic State University and University of Southern California, majoring in economics and public administration, then served the city of Los Angeles in a number of capacities. He also worked as general manager of the Los Angeles Department of Water and Power, the largest public utility in the country.

The army, he said, set him on the right path for life. "The discipline and the chance to grow up were invaluable to me," he said. Today at 76, he is retired, participates in volunteer work, cooks a lot, and spoils his grandkids, ages 7 and 5.

"I see my two beautiful grandchildren often," McCarley said. He has been divorced twice and today is single. "The grandkids have seen the tomb. The joke is that I'm old enough that I actually knew General Custer."

Sgt. Edward Brown, Bluffton, South Carolina, Served at the Tomb of the Unknown Soldier from 1969 to 1971
"I was drafted," Brown told LifeZette of his two years in the military. "I was born and raised in Wallingford, Connecticut — a small town back then. I reported to Fort Dix, New Jersey. At that time Fort Dix was the only training camp with a real, honest-to-gosh Vietnam village for training purposes. I did my basic and infantry training there, and prepared to ship out to Vietnam."

Four soldiers from two different companies then learned they would not be going half a world away to fight. "I was ready to go to the West Coast to ship out, and my orders got changed," Brown remembered. "Why, I don't know. I was to report to Fort Myer, Virginia."

Brown was assigned to The Old Guard. "For the first three months I was in the marching unit and we were burying quite a few guys a day in Arlington Cemetery," he recalled somberly. "Soldiers who had been killed in combat, or officers who died. There was a marching platoon that brought them to the grave in the caisson, pulled by the horses. I did that for three months, then went from Arlington Cemetery duty to the White House to perform different ceremonial duties, such as presenting arms on the White House lawn. It was Nixon's first term, so he had dignitaries coming in all the time," said Brown. "There was an opening at the Tomb of the Unknowns, and I applied. I was finally accepted to 2nd Relief."

Brown enjoys remembering his service at the tomb. "It was very special. My parents were very proud," he said. "My biggest moment was when my folks were there, watching me walk the mat. I didn't see them, of course. I was so focused. My dad served in the OSS — Office of Strategic Services — in WWII. OSS was a precursor to today's CIA. It was an unforgettable moment for sure for my dad to see me guard the tomb."

Brown also recalls the demands of the job. "You have to be very committed to be a tomb soldier. Other than being in battle, it's one of the more demanding jobs in the military. That said, it is very humbling, and a great honor. Being able to guard and respect folks who died for you — those who lost their families and lost their identities in war — is an extremely humbling thing."

Brown also remember the rigors of the role. "When I went on as a tomb sentry in the late 60s there were four of us, four sentinels per relief, plus a sergeant. You walked one hour on, then had three hours off during the day. Then we went to two-hour shifts."

During the summer, Brown said, there would be as many as 300 visitors during a guard change. "Walking your one hour, it was really something to feel the respect. You could hear a pin drop during the changing of the guard."

Like the decade in which McCarley walked the mat, Brown served at the tomb during a time of change in America. The Beatles had disbanded, Apollo 13 experienced its ill-fated moon mission, and the Vietnam War was dragging on. "There were war demonstrations, of course, and a lot going on in D.C.," said Brown. "It was a unique time for this country."

Brown remembers one unusual highlight from his time as a tomb guard. "We were the first ones to get a color television," he said. "Someone donated it to the tomb."

What does Brown want Americans to know during this solemn Memorial Day weekend and beyond? "Our children should know more about the people who fought and died for them," he said. "People should have a basic education about Arlington Cemetery. People don't realize that Medgar Evers, Joe Louis, and many civil rights leaders and athletes are buried there. Dr. James Naismith, the inventor of the game of baseball, is laid to rest there. People you would never guess are laid to rest there."

Brown is proud of his time serving his country. "The tomb guard badge is really special to all of us," he said. "It's the least awarded badge in the army, and the second-least awarded badge in the whole military. The first is the astronaut's badge."

Where is Brown's badge now? "Mine is hanging on the wall," he said proudly.

After Brown completed his two years of military service, he got married and went to work, entering the sales profession. He had his own business outside of Washington, D.C., for 44 years, selling kitchen cabinets.

Now retired, he is married to his second wife and has two stepsons. "They are great guys," he said proudly.

Brown brought his grandchildren, ages 13, 11, 8, and 4, to visit the Tomb of the Unknown Soldier three years ago. "They were surprised by it all, I think, and they saw what you have to do, the serious nature of the job," he recalled. While they were there, he and his family went into the living quarters of the tomb.

"There's a board that has all the prior sentinels' names on it, starting from 1958," he said. "They were able to see my name right up on the board."