A team of conservators and researchers raises the turret of the USS Monitor out of the ocean on Aug. 5, 2002. (NOAA)

For 140 years the two Yankee sailors lay entombed in the turret of the USS Monitor, doomed shipmates aboard the sunken Civil War vessel 40 fathoms down and 16 miles off Cape Hatteras.

Their remains were recovered when the turret was brought to the surface in an amazing feat of marine archaeology and engineering in 2002.

Next month, after a decade of trying to learn their identities, the Navy plans to bury the comrades as unidentified in Arlington National Cemetery with full military honors.

The funeral, scheduled for March 8, will mark 40 years of research into the Monitor by the Navy, the National Oceanic and Atmospheric Administration, the Mariners’ Museum in Newport News, Va., and many other organizations.

And it will lay to rest perhaps the last of over 600,000 soldiers, sailors and Marines who perished in the long ago war for the Union. The nation is currently commemorating the sesquicentennial of the war, which ran from 1861 to 1865.

“These may very well be the last Navy personnel from the Civil War to be buried at Arlington,” Navy Secretary Ray Mabus said in a statement Tuesday. “It’s important we honor these brave men and all they represent as we reflect upon the significant roleMonitor and her crew had in setting the course for our modern Navy.”

The Monitor is famous for battling the Confederate ship CSS Virginia, formerly the USS Merrimack, on March 9, 1862, at Hampton Roads, Va., in the first fight between ironclad warships.

Almost 10 months later, the two sailors were aboard the Monitor when it sank in a gale off the North Carolina coast on Dec. 31, 1862. The ship capsized and settled on the bottom upside down.

Most of the 63 crewmen escaped. Sixteen men perished; the bodies of the other 14 were never recovered.

The two unidentified men — an older sailor, about 35, who walked with a limp, wore a gold ring and often had a pipe clenched between his teeth, and a younger man, about 21, with a broken nose and mismatched shoes — were trapped in the turret.

More than a century later, their almost-complete skeletons were found, one on top of the other, amid a tangle of huge guns and debris. The turret resides at the Mariners’ Museum today.

On March 7, representatives from the Navy and NOAA will escort the remains from the military’s Joint POW/MIA Accounting Command in Hawaii, where the bones have undergone study, said a Navy spokeswoman, Lt. Lauryn Dempsey.

The next day the sailors will be borne to their graves in two caskets on a horse-drawn caisson during an interment ceremony at 4 p.m. The exact burial site was still being determined Tuesday.

“It’s extraordinary on a number of levels,” said David W. Alberg, superintendent of NOAA’s Monitor National Marine Sanctuary. “There’s something comforting to know that, no matter what you go through, what sacrifice you make, that the nation’s promise to look after you, bring you home and honor you is as good 150 years later” as it is was back then.

“Here we have two men who were lost in a storm, forgotten by even many of their descendants,” he said. “But the nation’s never forgotten.”

The wreck of the Monitor was located in 1973 by a Duke University research ship in a stormy region called “the graveyard of the Atlantic.”

The study of the sailors’ bones yielded DNA but few other clues: the younger man’s broken nose, and indications of a limp in the older man, the ring on a finger of his right hand and a groove in his front teeth where he bit down on his pipe.

The identities of all the lost Monitor sailors are known, and many crew members are depicted in old photographs — including a famous series taken on the ship by photographer James F. Gibson in July 1862.

But it was not known which identities might go with the recovered remains.

Last year, at the Navy Memorial in Washington, experts from Louisiana State University displayed clay facial reconstructions of the two men, based on models of their skulls.

Experts hoped that the clay images might, through public exposure, provide leads to the sailors’ identities.

Officials noted a strong resemblance between the reconstructed face of the older sailor and that of the Monitor’s Welsh-born first-class fireman, Robert Williams, 30.

In two of Gibson’s pictures, Williams appears in a cap and a mustache, standing with his arms folded. He is surrounded by other members of the crew, who lounge on the deck, playing checkers and smoking pipes.

But investigators could come up with nothing more definitive, and the sailors must now go to their graves unidentified.

Officials said the case will remain open, should further information be discovered.