In 2019, a team of researchers confirmed that a wooden wreck resting off the muddy banks of the Mobile River in Alabama was the Clotilda, the last known ship to bring enslaved people from Africa to the United States.

Now, the researchers say they have made another startling discovery: The wreck is remarkably well-preserved. As much as two-thirds of the original structure remains, including the hold below the main deck where 110 people were imprisoned during the ship’s final, brutal journey from Benin to Mobile in 1860.

The researchers said it was possible that DNA could be extracted from the sealed, oxygen-free hull, which is filled with silt. Barrels, casks and bags used to stow provisions for the captives could also be found inside, they said.

“It’s a time capsule that is cracked open and it survives,” said James Delgado, an archaeologist who has been helping to study the site on behalf of the Alabama Historical Commission.

Dr. Delgado said researchers planned to remove sediment and wood from the Clotilda, which could be analyzed to determine if there was DNA that could be traced to a particular region or linked to descendants.

Last month, the Clotilda was listed on the National Register of Historic Places, giving it added protection as officials in Alabama continued to research the site to determine what should happen to the wreck. The revelation that the ship was largely intact was reported this week by National Geographic.

Historians and descendants of those who were transported on the ship hope that the research will draw attention to the stories of the enslaved people on board, who eventually formed their own community, Africatown, in Mobile, after the end of the Civil War.

“The ship has been incredibly important in the sense that it has shed light on the whole story,” said Sylviane A. Diouf, a historian who has written about the Clotilda. “The story of the people is the most important, and they were on the Clotilda for about six weeks.” It was a place, she said, that they never wanted to see again.

The Alabama Historical Commission’s report detailing why the Clotilda should be added to the National Register of Historic Places said it “provides a unique and horrific archaeological opportunity” to enter the hold where men, women and children were transported during the 45-day voyage from West Africa to Alabama.

The space, which had previously held lumber, was dark, cramped and suffocating: 23 feet long, 18 feet to 23 feet wide and less than seven feet high.

“It’s very chilling,” said Darron Patterson, the president of the Clotilda Descendants Association, who said his great-great-grandfather, Kupollee, arrived in Alabama on the ship as an enslaved teenager.

Mr. Patterson said he hoped that Alabama officials could raise the vessel from the river and display it.

“It takes a certain amount of evil to carry out something like that, to treat human beings like cargo,” Mr. Patterson said. “We would like for that ship to be on display so the world never forgets.”

Such an undertaking would be costly, if it is even possible, Dr. Delgado said.

The Alabama Historical Commission said it had hired researchers, engineers and others to study the site, including the composition of the sediment, the river current and the effects of biological decay on the wreck.

The data will be used to develop a plan to address the effects of erosion and to determine if the site should be stabilized. The study will also examine whether the riverbed could be used to erect a memorial, the commission said.

“It is a tremendous duty to ensure that Clotilda is protected, and the Alabama Historical Commission takes its role as the legal guardian of Clotilda very seriously,” Lisa D. Jones, the commission’s executive director, said in a statement. “The Clotilda is an essential historic artifact and stark reminder of what transpired during the trans-Atlantic slave trade.”

The Clotilda’s final voyage was undertaken illegally because Congress had banned the importation of enslaved people more than half a century earlier.

After the schooner arrived in Mobile and transferred the captives to a riverboat in July 1860, the Clotilda’s captain, William Foster, burned and scuttled the ship to hide evidence of his illicit trade, Dr. Delgado said. The ship has remained in the same spot in the Mobile River ever since, researchers said.

After the Civil War, some of the people who had been transported on the Clotilda asked their former enslaver, Timothy Meaher, who had organized and financed the voyage, to give them land, said Dr. Diouf, the author of “Dreams of Africa in Alabama: The Slave Ship Clotilda and the Story of the Last Africans Brought to America.”

When Mr. Meaher refused, the formerly enslaved workers bought land from him and others, Dr. Diouf said, and formed Africatown, where African languages were spoken for decades.

“It’s, of course, a story of resistance,” she said. “They, from Day 1, acted as a community and as a family and they continued to be very active after they became free.”

Joycelyn Davis, who lives in Africatown and is a descendant of Charlie Lewis and Maggie Lewis, who were enslaved on the Clotilda, said she hoped that archaeologists could find barrels and other items as well as DNA that could be linked to descendants.

“I am anxious to see what they can bring up and what they can preserve,” she said. “Finding the ship brought us closure. With it being intact, it’s just mind-blowing.”

The stories of Africatown and the survivors of the Clotilda have drawn broader interest since researchers confirmed the identity of the wreck in 2019 after it was found by Ben Raines, a journalist and filmmaker and a son of Howell Raines, a former executive editor of The New York Times.

“Descendant,” a documentary about the Clotilda and the descendants of those on board, will be featured at the 2022 Sundance Film Festival. The descendants themselves plan to hold a festival in Mobile in February.

“We want people to never forget,” Mr. Patterson said, “that even though there was a certain amount of evil involved, those people in the cargo hold were able to overcome.”