As a girl, the Rev. Holly Haile Thompson remembers tagging along with her mother, Elizabeth Chee Chee Thunder Bird Haile, into fourth grade classrooms each autumn to give lessons on Native American history.

Her lessons were larger than passages from a history textbook; they were lived experiences for Thompson, a Shinnecock Indian who grew up on tribal land in Southampton.

Thompson, the first Indigenous woman to be an ordained minister in the Presbyterian Church, carries her mother's spirit in her own lessons on Shinnecock history.

"It does me no good to take it with me wherever I'm going, so I need to leave all that information here," she said Saturday after presenting "Shinnecock 101" at The Church, an 1832 Methodist church reimagined as an art, performance and lecture hall in Sag Harbor.

Saturday's program, meant to celebrate Shinnecock culture and share its history, is part of an ongoing exhibition, Eternal Testament, on display at The Church through June 1. The show features contemporary native art with themes of land loss, assimilation and spirituality.

Part of The Church's mission is to honor Sag Harbor's roots, executive director Sheri Pasquarella said.

"We like to think about all of the histories that are embedded in the land that we occupy and the idea of Sag Harbor past, present and future," Pasquarella said.

Thompson's meditative presentation covered both the beauties and atrocities of 400 years of Shinnecock history, first exploring how the matriarchal society functioned with women as protectors, tending to sacred crops like corn, beans and squash.

"Our DNA is in this land, and this is the land that takes care of us," Thompson said to an audience of about 50 people.

Reverence for the land was evident as Thompson told the history of annual gatherings like the June Meeting, held to "welcome the flowers … giving thanks when the corn that you have just planted has grown to the size of a squirrel's ear," and the annual powwow held on Labor Day weekend for nearly 80 years.

She proudly displayed her mother's deerskin regalia and grandfather's Shinnecock scrub named for the scrub oak branches that form the cleaning tool.

But Thompson's presentation was also a painful reckoning of injustices. Sag Harbor's history of whaling was a boon of wealth to white settlers but left many Shinnecock men impoverished, a generational trauma that impacts life on tribal land today, she said.

According to U.S. Census data, the poverty rate in the Shinnecock Nation is 20.6%, almost three times the rate of Suffolk County as a whole, Newsday reported in February.

Some in the audience were surprised to learn that members of the Shinnecock Nation were among the thousands of children forcibly removed from their communities and taken to Indian boarding schools to assimilate into American culture.

"These things seem so far away. You want to say 'Oh, that happened in Canada, or that happened out west,' " said Karen Murray, of Southold. Murray said the presentation helped portray "a bigger idea of the whole story."

Sandy Muller Raynor, of North Sea, said she has lived her whole life in the area and has been curious to know more about the Shinnecocks.

"I'm realizing how little I really understood," Raynor said. "There's more we could do to be good neighbors in return for what was given to us."

Thompson's talk also snapped attendees into the present day, as the nation continues to battle New York State and Southampton Town in court over two digital billboards flanking Sunrise Highway and a gas station plaza planned on their Westwoods property in Hampton Bays.

Thompson, holding a wampum belt that symbolizes peace, said she hopes to play a role in correcting centuries of "willful misunderstanding" and cultivating more understanding about indigenous culture and history.

"Shinnecock people are rather peaceful, and we have been very patient, hoping justice would come our way," she said. "We only have a few acres left to protect."