Groton — Filmmaker Katrina Browne remembers paging through a booklet her grandmother wrote about their ancestry and seeing a reference to slavery and their distant relatives.

“I haven’t stomach enough to describe the ensuing slave trade,” her grandmother Rosalind Howe Sturges Allen wrote next.

Those references compelled Browne to begin researching her ancestry and ultimately produce and direct "Traces of the Trade: A Story from the Deep North," a documentary about her Rhode Island family and its role in a slave-trading empire.

“Those two sentences were enough to scream at me on the page,” Browne said.

On July 25, Browne will lead a discussion at Groton Public Library after a showing of the film at 7 p.m.

“It’s not about a guilt trip,” she said of the film. “It’s about facing the facts and seeing what that says to us about our present day realities.”

Browne’s discussion is part of Groton Public Library’s “One Book, One Region,” program series, which this year focuses on Yaa Gyasi’s book “Homegoing,” which portrays the impact of the slave trade on generations of a family.

Browne’s relatives not only engaged in slave trading, but became the biggest slave trading family in U.S. history. Browne is a descendant of Mark Anthony DeWolf, the first slave trader in the family.

The DeWolf family transported more than 10,000 African slaves across the Middle Passage over the generations, according to the film. Boats sailed from Bristol, R.I., to West Africa, and traded rum for human beings, then brought the slaves to plantations or sold them at auction.

The film premiered at the Sundance Film Festival in 2008 and then aired on PBS, reaching more than 1.5 million people.

Yet there’s a continued perception that slave trading occurred only in the South, Browne said.

“When I show the film anywhere in the country, the vast majority in the audience, their jaws are dropping,” she said.

Her goal is to encourage people to talk about the role of the North as well as the South in slavery, the personal feelings of white and black Americans and the racial inequities that exist today. Too often, Browne said, white Americans become defensive when approached with racial issues, because they don’t want to be held personally responsible or labeled as guilty.

“We so badly don’t want to be blamed, and we take it personally when black Americans are saying, ‘I’m not trying to guilt trip you,’” she said. “'Get over yourself and work on racial equity.'”

d.straszheim@theday.com