At 8 p.m. Thursday night, dozens of Minnesotans will file on to a motor coach bus. They're traveling 900 miles south and 150 years back — to Nashville, Tenn., and that city's often overlooked Civil War battlefield.

They're going to commemorate the sesquicentennial of the bloodiest single day of the war for Minnesotans, when 87 soldiers and officers were mowed down busting through the Confederate lines on Shy's Hill on Dec. 16, 1864, in the last major battle of the war. Their visit comes on the heels of Veterans Day.

The Minnesotans will unveil a marker next Sunday morning "to cement the significance of what happened that day," said Ken Flies, perhaps the state's leading expert on the battle and the force behind the new marker.

It will be engraved with the words of an Iowan, a "lowly private" named Jacob Milton Benthall, whose tender account of the horror might be "the most eloquent and well-written piece" Flies has come across in decades of research:

"… comrades who have grown as dear to us as brothers lie dotting the steep hillside, their battles ended, their warfare over. Never more will they press with us shoulder to shoulder as the bristling steel points sweep resistlessly on, never more in our hours of glee will their voices join in the merry jest or fill the air with laughter — they are gone.

We buried them where they fell upon the field of honor. Rough but kind hands scooped out their narrow beds, and with all of women's tenderness we laid them to rest in a soldier's sepulcher.

And the everlasting mountains in the shadow of which they lie shall be their eternal monument; year after year the forest trees will shed their crowns of glory over them, and day by day the winds, as they sigh through the Brentwood Hills, will chant a low, sad requiem to their memory."

Just how Flies unearthed those poignant words and connected them to their long-forgotten author is an example of the doggedness Civil War buffs continue to employ to tell the tales that shaped the state and nation.

Like many making the trek to Nashville, Flies has a personal connection to the bloodshed. His great-grandfather, James Foster, died in Tennessee, like many of the boys from Wabasha County's Company C of the Tenth Minnesota Infantry.

Their regiment was bivouacked in Mississippi in early 1865, bored while awaiting transport to Mississippi for the war's final skirmishes. So the educated guys in the group decided to publish one edition of a regimental newspaper they called The Tenth Minnesota News.

A story headlined "The Final Charge at Nashville" included only the initials J.M.B. at the end. Flies figured the story was penned by Col. James Baker, an educated lawyer and secretary of state capable of such eloquence.

When he dug deeper, Flies realized Baker wasn't in Nashville because he'd been named a provost marshal in St. Louis. So Flies pored over Tenth Minnesota records, finding only one soldier with the initials J.M.B.

"I was amazed to discover that the author who showed such command of the English language was not an officer but indeed a lowly private from Iowa," he said.

John Benthall, as he was known, was born in Massachusetts in 1832, attended the Lowell Academy and moved to Quasqueton, Iowa, to enter the milling business in 1855. His wife, Mary, died in childbirth in 1858 and Benthall sent his infant son, Fred, back east to be raised by relatives.

Flies remains baffled why Benthall, perhaps distraught, wandered north to enroll in the Tenth Minnesota in 1862 when a group of his Iowa neighbors signed up around the same time. He was one of only three members of Company C not from southern Minnesota.

"It's a mystery worthy of further research," Flies said. And that will be tough because the Civil War dispatches Benthall sent back to his local newspaper in Independence, Iowa, perished in a fire at the paper's office in the early-1900s.

Flies has learned that Benthall returned to Iowa after the war, remarried in 1875 and had two more kids before moving to Boston in 1901 to reunite with his son. He died in 1908 at 76. He's buried in Lowell, Mass., with his parents and sister.

Flies' research has inspired cemetery officials there to update his grave to show his Civil War contributions. In the meantime, his words will be etched into the historic marker in Nashville — where the winds sigh through the hills.

Curt Brown's tale on Minnesota's history will appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com