I grew up on Gallatin Street NW, across the street from the back of Rock Creek Cemetery. We always played hide-and-seek there. What can you tell me about the casket encased in glass near the small lake?

— Sylvia Eleni Simons Trembelas, Pentagon City

I can tell you that the man buried underneath the casket was very concerned about his mortal remains, so he left detailed instructions on how he wanted to be interred.

That’s just one of the odd tidbits connected to Levi Ziegler Leiter, the dry -goods merchant who rests in section L 24 at the cemetery, which is off North Capitol Street.

The tomb of Levi Z. Leiter, in Rock Creek Cemetery, is topped by a glass structure. Inside is a white marble sarcophagus. Somewhere underneath is Leiter, a wealthy dry goods merchant. (John Kelly/The Washington Post)

Leiter was born in Washington County, Md., in 1834. Like so many striving young men of his generation, he went west. He moved to Chicago in 1855, where he worked as a clerk at a wholesale drapery house. One of his fellow clerks was a man named Marshall Field.

If that name sounds familiar, it’s because of the famous Chicago department store which the two founded along with another partner. Leiter sold his portion of the business to Field in 1881.

That made Leiter fabulously wealthy, a fortune he only enhanced with commercial real estate deals, coal mine leases and stock market speculation. Answer Man doesn’t know why millionaires no longer move to Washington, but back in the Gilded Age, this was common. Leiter had a grand mansion built on New Hampshire Avenue near Dupont Circle.

Leiter died in 1904 while summering at Bar Harbor. His funeral was held at St. John’s Episcopal Church, across from the White House. And then he was buried.

“It was the wish of Mr. Leiter that . . . precautions be taken against disturbance of his body,” wrote the New York Times after the interment. The precautions included digging a hole 12 feet square in the plot purchased at Rock Creek Cemetery. Two feet of concrete was poured in. This was covered over with a grid of steel beams with space left for a casket. This was lowered into the recess. More steel beams were bolted across the casket before the chamber was filled with concrete. It was as if the mortal remains of Levi Z. Leiter were encased in solid rock.

“Only an earthquake or heavy charges of explosives could move the mass,” wrote the Times.

Why did Leiter stipulate that his grave should be so overbuilt? Was it because he feared coming back as a zombie, feasting on human flesh, and scouring the land looking for deals on wholesale drapes and haberdashery?

No, of course not. It was because of what had happened to A.T. Stewart.

Like Leiter, Alexander Turney Stewart was a retail giant. His Manhattan department stores — the largest dubbed the “Iron Palace” — revolutionized the shopping experience. He died in 1876 and was buried in the churchyard of St. Mark’s in the Bowery.

Two years after his death, grave robbers broke into his vault and spirited away his putrefying remains. Through an intermediary, they contacted Stewart’s widow and demanded $250,000 for their return. It took another two years before the two sides could come to terms. Mrs. Stewart finally paid $20,000 for a satchel full of bones, presumably her husband’s.

Was Leiter right to be worried? Well, three months after his interment in 1904, The Washington Post reported that “ghouls have formed a plot to rob the grave in the cemetery of the remains of Levi Z. Leiter and hold them for a large ransom.” Extra watchmen were placed at the graveyard, but the superintendent said he wasn’t too worried. All that concrete was holding Leiter tight.

As for the glass coffin, it was a later addition to the grave site. The Leiter tomb is topped by a handsome white Carrara marble sarcophagus that is covered in bas-relief carvings.

“The apocryphal story is that the sarcophagus there now is the second one,” said Jim Jones, senior warden of St. Paul’s Episcopal Church. Although he can’t confirm it, supposedly the first sarcophagus melted away in the elements — Carrara marble is very porous — and the glass house was put there for protection. Of course, it would take a lot of erosion to get down to Leiter’s corpse.

Oh, another thing about Leiter: He and his wife, Mary, had one son and three daughters. The oldest daughter, Mary Victoria, married an English nobleman: George, Lord Curzon of Kedleston, one-time viceroy of India. Supposedly, the fictitious Cora Crawley, countess of Grantham on “Downton Abbey,” is modeled after this Leiter daughter.

And just to play out this interesting story even further, one of Mary Victoria’s daughters, Cynthia, married Sir Oswald Mosley, the British fascist.

What are you waiting for? Send your question to answerman@washpost.com. To read previous columns, go to washingtonpost.com/johnkelly.