The sword, long thought to have been lost, was used by Colonel Robert Gould Shaw in 1863. Stuart C. Mowbray

After the sword of Colonel Robert Gould Shaw was gifted to the Massachusetts Historical Society by descendants of Shaw’s sister earlier this year, staff from the organization used their detective skills to scour through old documents and trace the journey of the weapon from its origins in England to its hiding place in the attic of a family home.

The sword, long thought to have been lost, was used by Shaw in 1863 as he led the 54th Massachusetts infantry, a courageous group of black soldiers, into battle at Fort Wagner in South Carolina.

The rare weapon — a replica of it can be seen on a bronze monument of Shaw and his infantry that stands outside of the State House, on Beacon Hill — was stripped from the colonel after he was shot and killed on the battlefield by enemy troops.

The stolen sword seemed doomed to obscurity and left history buffs collectively scratching their heads as to its precise whereabouts, with few clues to go by.

But when the sword fell into the hands of Anne Bentley, curator at the historical society, and staff from the organization, they set to work to unravel the mystery.

Below is the chronology of Shaw’s sword’s journey, as explained by Bentley:

November 1860: Robert Gould Shaw is enlisted in the Seventh New York Infantry Regiment.

May 1861: Shaw is commissioned second lieutenant of Company H of the Second Massachusetts infantry, an elite regiment, according to the historical society.

July 1861: Shaw is commissioned first lieutenant of the same regiment.

August 1861: Shaw moves up the ranks and is commissioned captain before his name is floated to command the country’s first African-American regiment, according to the historical society’s website.

March 1863: Shaw is commissioned as a major for the newly formed 54th Massachusetts infantry, who he would later famously lead into battle at Fort Wagner, in South Carolina.

April 1863: Shaw is commissioned colonel of the 54th Massachusetts. It’s around this time that Shaw’s uncle, George R. Russell, ordered an officer’s sword from Henry Wilkinson, a master swordsmith from England.

May 1863: Wilkinson sword number 12506 is “proofed,” according to Wilkinson’s archive records. It’s later etched and mounted, and sold to C.F. Dennett, Esq., historical records show. The Massachusetts Historical Society concluded, “Clearly this sword was ordered as soon as possible, after [Shaw] received his commission as Colonel of [the] 54th.”

June 1863: Shaw writes a letter to his mother that says his “Uncle George” has “sent me an English sword, and a flask, knife, fork, spoon.” But, he adds, “They have not yet come.”

July 1863: Shaw writes to his father: “A box of Uncle George’s containing a beautiful English sword came all right.” According to the historical society, this is Wilkinson’s sword number 12506, a regulation infantry sword with the initials R.G.S. — Robert Gould Shaw — etched on it.

July 4, 1863: Shaw wrote to his father again and said, “All the troops, excepting the coloured Regiments, are ordered to Folly Island. . . . P.S. I sent you a box with some clothes and my old sword. Enclosed is receipt.”

July 16, 1863: The 54th Massachusetts participates in the Battle of Grimball’s Landing, on James Island. Historians say Shaw likely used his sword in this battle, which was the first experience “under fire” for the regiment, according to the historical society.

July 18, 1863: The assault on Fort Wagner takes place, and Shaw is shot in the chest while standing on the parapet, “sword in hand,” the historical society said. “Overnight, his body was robbed of personal effects and arms and stripped to underwear.” Sources, the organization notes, have differing theories about who the culprits of the theft were.

July 19, 1863: Shaw is buried in the rifle pits with his men.

1865: An excerpt from Solon A. Carter’s paper “Fourteen Months’ Service with Colored Troops,” which can be found in the book titled “Civil War Papers,” printed in 1900, gave historical society staff a major clue in documenting the recovery of the sword late in the war, Bentley said:

In July [1865], upon leaving the service, the late Assistant Adjutant General was charged by General Paine with the duty of restoring the sword to Colonel Shaw’s father, and upon arrival at this home, opened a correspondence with Mr. Francis George Shaw informing him of its recovery.

The sword in question proved to be the one carried by the gallant colonel and was identified by the initials R.G.S. delicately etched upon the blade.

In a postscript to one of his letters Mr. Shaw wrote,“The sword was a present to my son from his uncle, Mr. George R. Russell, who purchased it in England and caused the etchings to be made there.”

June 3, 1865: A letter written by Brigadier General Charles Jackson Paine to his family corroborated Solon’s account. Paine said the sword was reportedly in the possession of “a rebel officer,” according to Bentley’s notes. Paine sent officers of the “US Colored Troops” to retrieve the sword and bring it to him. The home was empty, but the sword was found after the area was searched.

March 2017: After a long gap where the sword’s whereabouts remained a mystery, it’s finally found in the attic of the home of Mary Minturn Haskins, who was married to Robert Bowne Minturn — Colonel Shaw’s sister’s grandson, and the father of the donors who gifted the sword to the historical society.

April 6, 2017: A member of the family e-mails Bentley explaining that Susanna Shaw Minturn, Shaw’s sister, was his great-grandmother “and apparently was very close to her brother [Shaw].”

The family presumes that the sword ended up in their mother’s home because it was passed on to their father. The sword might have hung on their father’s childhood bedroom wall, the family said.

April 17, 2017: The family gifts the sword to the Massachusetts Historical Society, as part of a larger gift including papers and portraits.

July 18, 2017: The sword will go on display at the Massachusetts Historical Society, more than 150 years after it was stolen from Shaw.