BRISTOL — Pam Clark saw the mural for the first time after moving here from Iowa in 1971. It hung above the meat counter at the old Almacs grocery store and showed scenes of the slave trade.

Clark, who now lives in Warren, remembers the painting so well because of one panel in particular that depicted a group of slaves getting off a ship. They had smiles on their faces, she recalled.

“With all the civil-rights stuff that had gone on, I just couldn’t believe it,” she said.

The mural seemed to symbolize a reluctance to acknowledge the reality of slavery and this town’s deep involvement in the trade that brought tens of thousands of Africans to the United States in the 18th and 19th centuries.

On Tuesday, Clark was one of more than 300 people who came to a screening at Roger Williams University’s School of Law of a documentary that shows the local ties to slavery by telling the story of Bristol’s DeWolfs, the foremost slavetrading family in U.S. history.

It was the first time Traces of the Trade: A Story of the Deep North was shown in Bristol. Interest in the film was so great, the university had to open a second room to accommodate the overflow crowd.

Katrina Browne, a DeWolf descendant who spent a decade making the film, expected a lot of people but not nearly the number that showed up for the evening screening.

“Since it’s about Bristol, it makes sense that people in Bristol would want to see it,” she said afterward.

But there was more to it, said Derry Riding, president of the Bristol Historical and Preservation Society, which co-sponsored the event. Various groups in town, in alliance with the public schools, have been working hard in recent years to raise awareness about the role the slave trade played in the local economy.

Elementary school students learn about it in a program that focuses on the town’s history. The historical society leads walking tours of New Goree, the neighborhood where descendants of slaves and other African-Americans once lived.

“I think there’s a little more effort now,” said Riding. “We acknowledge our history.”

But that wasn’t always the case. For years, some people in town didn’t want to talk about where the money came from for Linden Place, a DeWolf mansion on scenic Hope Street, and other stately homes in the downtown historic district.

Riding tells a story of when Browne applied for a permit to start filming the documentary around town. Some town employees Browne spoke with knew nothing of Bristol’s ties to slavery, said Riding.

Browne herself didn’t know anything about her family’s leading role in the slave trade until she was an adult. In 1996, while she was in seminary school in California, her grandmother sent her a family history. It included a reference to three generations of slave traders in the family but offered little more detail.

Browne started exploring her family’s past. What she found haunted her.

From 1769 to 1820, the DeWolfs sailed from Bristol to West Africa, where they traded rum for African slaves. Some of the thousands of captives were shipped to the five coffee or sugar plantations owned by the family in Cuba. Most were sold at auction in the United States. The family grew wealthy, opening its own bank, insurance company, auction house and distillery, and continued buying and selling slaves illegally well after the federal ban on the trade took effect in 1808.

In 1998, Browne decided to make a film about the family’s past and her efforts to come to grips with it. She wrote to 200 DeWolf descendants, asking them to accompany her on a trip to Bristol, Ghana and Cuba, all stops on the slave trading route of their ancestors. Only 60 relatives replied and 9 decided to go with her.

The documentary traces their journey and its effect on them. At one stop in Ghana, they were confronted with the past misdeeds of their family.

“Are you not ashamed of coming here?” a local schoolgirl asks them.

Browne has screened rough versions of the 85-minute film about half a dozen times outside Rhode Island since 2003. She has been working with the Providence-based Rhode Island for Community and Justice for the past several months and they’ve so far shown it five times around the state, including last week at the Providence Black Repertory Company and Tuesday’s screening in Bristol.

The response has been sharply divided along generational and racial lines. Browne and Nanda Shewmangal, of Rhode Island for Community and Justice, said that whites and older African-Americans have generally responded positively. But many younger African-Americans have reacted with anger and said the film doesn’t speak to them.

“They say they already know this so there’s nothing in it for them,” Browne said. “They’ve said it’s a film for white people.”

There has also been a strong response — both positive and negative — to the issue of reparations, something discussed at length in the film.

Browne says she supports scholarships and other programs that would be financed by the government and corporations for disadvantaged African-Americans and hopes the film will help generate action. But she admits that such initiatives aren’t enough. She quotes from one of her relative’s African-American friends who appears in the documentary.

“Maybe reparations are a process, not an endpoint,” she says.

There were concerns that some people in Bristol would disapprove of the film, said Riding. But after it was screened Tuesday, the audience responded positively.

Outside the lecture hall where the documentary was shown, Harry Nicolas, an activist visiting from Haiti, called it a powerful tool.

“A film like this can offer hope just to be able to talk,” he said. Nicolas is visiting the United States to try and build support for the creation of a “memory village” in Haiti depicting slavery. “Talking is a step toward healing.”

Gary Watros, a Bristol resident, said the country needs to acknowledge the mistakes of the past.

“We have yet to apologize for some really serious wrongs,” he said.

A woman in the audience who said she was from Bristol praised Browne for telling the story of the local slave trade.

“Thank you for bringing it out,” she said, “because it’s been a long time in coming.”

As for the mural Pam Clark saw in 1971, Ray Battcher, the librarian at the Bristol Historical and Preservation Society, said it was taken down years ago. Almacs has since been replaced by another supermarket.

Battcher isn’t sure but he thinks the town has the mural in storage somewhere.

akuffner@projo.com