MEDFORD — Joseph McGill Jr. stood before the group to share his experiences sleeping in more than 60 slave quarters nationwide.
What the African-American preservationist could not foresee was the stunning revelations that would unfold in a matter of hours.
Three of the 10 guests who signed up to join McGill for a sleepover in the only freestanding slave quarters north of the Mason-Dixon line would acknowledge that their families enslaved Africans.
“It’s a first,” said McGill, 53, calling it “a good thing.”
“This is the highest concentration of descendants of slave owners that I have shared a space with overnight,” he added.
McGill’s lecture on the Slave Dwelling Project he founded and the overnight that followed were the culmination of the Royall House & Slave Quarters annual Giving Voice program fund-raiser, in which donors paid $50 to hear McGill speak and $200 to sleep in the austere 18th-century Medford dwelling of the largest group of enslaved Africans in Massachusetts.
“As a descendant of slave holders, I just feel I had to come and pay my respects,” said Reverend Fred Small, 61, a New Jersey native and senior minister of First Parish in Cambridge, a Unitarian Universalist church. “I was well into adulthood before I realized there were small numbers of slaves – enslaved Africans – owned by my New England ancestors.”
He was not alone in mustering the courage to share the family secret and shame.
Jamaica Plain poet Catherine Sasanov unearthed wills that proved title was held to 13 enslaved Africans in the Missouri Ozarks and up to 26 in Williamson County, Tenn.
“In my great-great-great-grandfather’s will, he basically said, ‘Sell ’em and split ’em up,’ ” she said.
Like Sasanov, Ellen Watters Sullivan, 58, of Eastham, has written about her family’s ties to slavery.
She recalled her father, a print journalist during the Civil Rights Movement, taking her to their family’s ancestral home in rural northwest Georgia and seeing a big house — and the little house out back.
“One of the things my father didn’t want to talk about was our slave-holding ancestry,” she said. “I knew there was something back there, but when I learned the extent, I was kind of shocked and devastated. It freaked me out.”
Others — like Robert Wolff, a professor of slavery, abolition, and memory at Central Connecticut State University, and Dee Mallon, a Newton textile artist — had other reasons to spend the night.
“I’m not sure what I hope to get out of it,” said Wolff, 48. “I have faith there’s something to get.”
For the last two years, Mallon, 57, has been writing a historical novel on indigo developer Eliza Lucas Pinckney and three enslaved Africans she owned.
“The minute I asked what were the lives of her slaves like, I just hit a wall,” Mallon told the group. “My research has taken me to some pretty remarkable places, including here.”
Ifé Franklin of Roxbury admitted she had reservations about sharing space with people who could have owned members of her family.
“I’m really surprised I don’t feel upset being in this room,” she said. “I’m here to listen and learn.”
For Franklin, 54, who was one of the four African-Americans in the overnight group, the chance to spend the night where her ancestors once slept filled her with gratitude.
She presented McGill with a gift of a small-scale version of a slave cabin at the center of her first solo textile art exhibit, “The Indigo Project,” which opened last fall in South Boston.
Like the original 8-foot-by-8-foot cabin she created — covered in pieces of indigo-colored cotton – it pays homage to enslaved Africans who lived and died producing the dye and the fabric.
Before the night was over, some pledged to financially support the efforts of the Slave Dwelling Project.
“What you do, Mr. McGill, is really important,” said Sullivan, on the verge of tears. “I see this as an opportunity to acknowledge and repair. It’s a form of reparation.”
McGill does not mince words whenever talk of reparations arises in relationship to his work.
“For me to gain access to these places, I’ve got to stay focused,” he said, noting that a lot of owners of former plantations he’s appealing to get nervous around that word: reparation.
Franklin said the slave-holding heirs in the room need to know that the discussion of reparations is not going away, nor should it.
“We built this country, brick by brick, blood, sweat, and tears, separated from family,” she said. “You need to do something, other than put up some monuments and apologize to me.”
For video with this story, go to www.bostonglobe.com/north. Reach Clennon L. King at email@example.com.