Timothy Shriver, middle front, and members of the Shriver family look at the 1835 Causten vault, a historic burial site that held the remains and artifacts of 16 individuals related to their family, at the Congressional Cemetery. (Amanda Voisard/For The Washington Post)

When Douglas Owsley first climbed down into the old and badly damaged Causten family vault at the historic Congressional Cemetery on Capitol Hill, he found rotting coffins, brass nameplates and human bones piled several feet deep on the floor.

“Whew,” thought Owsley, a forensic anthropologist at the National Museum of Natural History. “This is going to be a lot of work.”

And it was. But after years of research, experts from the Smithsonian Institution were able not only to repair the vault but also to sift through and identify the skeletal remains. In so doing, they found an unexpected connection to the influential and politically connected Shriver family — of Kennedy, Peace Corps and Special Olympics fame.

From that dusty pile of splintered wood and bone and broken glass, they were able to piece together people’s stories — the Civil War surgeon, the merchant who fought in the War of 1812, the little boy whose death prompted his grieving father to build the vault — and reconnect a family to its past.

On Wednesday afternoon, after a memorial service at the cemetery chapel, the remains of 16 people were reinterred in the Causten vault, some in plain white boxes, others in their original cast-iron coffins. Then the arched black door was locked.

Douglas Owsley of the National Museum of Natural History discusses child-size caskets that had been inside the 1835 Causten vault. (Amanda Voisard/For The Washington Post)

Tim Shriver, chairman of the Special Olympics, said he had not known anything about these ancestors before his family was contacted by cemetery officials. But when Owsley and others showed him photographs of some of the deceased, he couldn’t help but look for a family resemblance.

Despite all the decades passed, and stories long-forgotten, he said, “it’s my family.”

Wednesday was a quiet afternoon at Congressional, with birds chirping among headstones worn down to nubs, obelisks listing downhill and the sharp-cornered markers of recent burials.

The cemetery, built in 1807, is the burial place for scores of congressmen and one vice president. Over time, though, the 35 acres became neglected. A few decades ago, the cemetery was an overgrown, dangerous place, a hideout for drug addicts and a target for vandals.

Now it is being slowly restored. A nonprofit organization was established to protect the cemetery, and a group of Capitol Hill neighbors who walk their dogs there raises money to help maintain the grounds.

The cemetery has its own following: amateur historians, people drawn to the evocative grace of epitaphs, those moved by the grave site of the first openly gay service member. Volunteers lead tours, each one unique, said Lauren Maloy, program director of the Association for the Preservation of the Historic Congressional Cemetery.

Some guides are fascinated by the symbolism of the carved butterflies, laurel wreaths and snakes eating their own tails. Some by the War of 1812; others by the famous people buried there. Margaret Puglisi, the association’s vice president, said she loves the science of the disintegrating stones.

Douglas Owsley of the National Museum of Natural History explains details of the 1835 Causten vault as the family’s descendants listen. (Amanda Voisard/For The Washington Post)

She is leading a survey of the cemetery’s 20,000 markers to determine how many need repair, a review she expects will take about five years. The Causten vault, damaged by water seeping in over the years, was in danger of collapse before its renovation.

“The vault had to be repaired,” Owsley said. “But this is really the story of a family.”

Over the past five years, a team of archaeologists and anthropologists analyzed the skeletons taken from the vault, the hardware on the coffins (which helps date the caskets) and personal artifacts found inside. Bones provide all sorts of information, Owsley said, from gender and age to lifestyle (years of heavy labor, for example, take a toll), diet and probable cause of death.

Deb Hull-Walski and others pored over cemetery and other records, pulling obituaries, military logs, wills and wedding announcements for those buried inside the vault. Piecing it all together, a family portrait began to emerge.

The vault included people who lived in the mid- to late 1800s, from a 14-day-old child to an 86-year-old man, descended from three distinct lines: Causten, Shriver and Carvallo.

The Shriver name was a surprise. And Carvallo startled Owsley, who in past research had relied heavily on records from a U.S. Army surgeon during the Civil War who bore the same name.

“Now I was looking at him,” Owsley said of Carlos Carvallo, holding the surgeon’s bones in his hands.

Owsley could trace the carving on Carvallo’s heavy belt buckle and know from the medal around his neck that he was Catholic. A man with a heavy mustache, dark beard and piercing gaze, he was the son of the Chilean ambassador and had been educated in South America and in Europe.

Carvallo moved out West with the Army, and the rough life there took a bitter toll on his family: Of six children, five died, four of them infants stricken by illnesses that today would be quickly cured by antibiotics.

“My heart goes out to him,” Owsley said.

After the memorial service Wednesday, several members of the Shriver family walked from the chapel to the vault, seeing for the first time its brick face, the cross overhead and the words carved on marble plaques: Inexorable Death’s Doings.

They peered inside, under a curtain of cobwebs and spiders skittering for cover, narrowing their eyes to adjust to the darkness. A woman asked in which corner the researchers had found the remains of the many children who had died.

Looking in at the clean, almost empty arched space, Tim Shriver asked Owsley about a new platform that had been added for the remains — and then added, lightly, “Are you going to make a note for future archaeologists?”