Dallas-based Heritage Auctions estimates the shackles are worth at least $10,000, but some Brown memorabilia has fetched much more. In 2007, a rare daguerreotype sold for $97,750 at a Cincinnati auction.
John Boling of Buhl, Idaho, whose family has long owned them, said his family hopes that whoever buys the shackles will display them publicly.
"We believe that history should be learned and understood," said Boling, whose great-great-great-grandfather, Hezekiah Atwood Jr., apparently obtained them shortly after Brown's execution on Dec. 2, 1859, in what is today West Virginia's Eastern Panhandle.
History long regarded Brown as a domestic terrorist, and some Southerners still do. Many scholars consider Brown and his raid to be flash points, hastening the start of the Civil War.
But many now see him as a martyr, ahead of his time in trying to end slavery. The Connecticut native spent months plotting to seize 100,000 weapons from the arsenal and use them to launch a guerrilla war with the slaves he believed would join him.
Yet the first casualty in the Harpers Ferry raid was a free black man, a baggage handler who bled to death while Brown's raiders grabbed hostages and holed up at a fire engine house. Within 48 hours, the rebellion was dead, along with at least four civilians, 10 raiders and a U.S. Marine.
Brown was tried for treason, murder and inciting a rebellion. He was hanged in Charles Town, and is buried on his former farmstead in North Elba, N.Y., now home to the John Brown Farm State Historic Site.
An official with New York's parks system said the state has no plans to bid.
"The raid didn't happen here, and we don't have the resources at this time," said Brendan Mills, manager of the site near Lake Placid. "If they were donated, we would take them,"
Much of the Harpers Ferry National Historical Park is devoted to the story of John Brown, but Superintendent Rebecca Harriett said Monday that she was unaware of the auction. Funding would also be an issue, she said, "especially on such short notice."
Don Ackerman, consignment director for the auction house, said historians had to sift through a lot of "murky family lore" to verify the shackles are authentic. Among the stampings are the initials ER, for a well-known Shepherdstown locksmith, Elijah Rickard.
Boling's ancestor served with the First Maine Volunteers in the Civil War and was in Charles Town at some point, perhaps to put down the rebellion, Ackerman said.
At least four newspaper articles published between 1889 and 1893 reported that Atwood obtained Brown's leg irons from an elderly black woman, providing her a substitute pair that he bought for $8.
The shackles were briefly exhibited at the Portland Historical Society in Maine after Atwood returned home. When he died, his widow gave them to his brother, James N. Atwood.
They later ended up at Plymouth Church in Brooklyn Heights, N.Y., where the Rev. Henry Ward Beecher stomped on them during sermons about slavery. Beecher was the brother of "Uncle Tom's Cabin" author Harriet Beecher Stowe, and Hezekiah Atwood Sr. had been a Congregationalist minister.
"When you're talking about historical objects like this ... it's not always possible to say with absolute certainty that it is what is," Ackerman said.
But "deductive reasoning" and the evidence he's reviewed provide 99 percent certainty. Nor has there ever been a contradictory claim of ownership.
"I'm satisfied that everything matches and makes sense," Ackerman said, starting with the fact that the same family has had the artifact for generations and that family was connected to Charles Town. The maker's marks appear genuine, linked to a well-known family of local locksmiths the jail would likely have used — and the jail acknowledged the shackles had been "liberated" after Brown's execution.
"All of those taken in totality," he said, "it's fairly convincing to me that these are the ones."
Online bidding ends Friday at 10 p.m. Central. Live bidding starts Saturday morning but can also be done by phone or through the Heritage website.
Associated Press writer Chris Carola contributed from Albany, N.Y.
Copyright 2013 The Associated Press.