Ten years ago, inspired by the book "Roots," Dorothy Redford, a welfare supervisor in Portsmouth, Va., began tracing her ancestry to Somerset Place, a huge rice and grain plantation near the Alligator River on North Carolina's sandy coastal plain.

Working on weekends and nights, and relying on plantation correspondence, interviews with descendants and scanty records that sometimes listed slaves by names like "Jupiter" and "Plato," Redford gradually pieced together her family's story.

Fascinated by what she found, she broadened her study to include the 20 other slave families who lived there from the plantation's beginnings in 1785 until the slaves' emancipation during the Civil War. Once the study was completed, Redford began the equally arduous task of finding those families' decendants for a reunion.

"The response has been overwhelming," said Redford, 42. "I think people were just so glad to find they were connected somewhere. Like most people, we have such a need to find out about our past."

Next month, more than 2,000 persons whose ancestors once labored as slaves on the 5,870-acre plantation are expected to travel there for what Redford said will be a joyous "homecoming," a reunion that she said is without precedent. Redford plans to decorate the plantation's cypress trees, planted by the slaves, with symbolic yellow ribbons and to give the decendants coded name tags that will group them by how far removed they are from slavery.

The Aug. 30 gathering, which will be attended by many Washington and Baltimore area residents, will be a "healing" and an opportunity to focus on the contributions that Somerset Place's families and their descendants made to America, Redford said.

The plantation, once owned by the Josiah Collins family and broken up after the Civil War, is now a state park about 35 miles from the town of Plymouth, and it will be open to the public for the reunion. Many who are going said they are repulsed by what happened to their ancestors at the plantation but are drawn, as if by instinct, to the reunion.

"It's a bit of nostalgia and a bit of history," said Maryland state Sen. Clarence W. Blount (D-Baltimore). "Pleasant or unpleasant, it's there, and you can't change it."

Like many of those Redford contacted, Blount said he had had no idea that his past was intertwined with that of the 20 other families who had lived on the plantation.

"I know that some people wouldn't even want to know," he said, noting that his great-grandparents, Dick and Patience Buck, worked the grayish North Carolina soil as plantation field hands and had 10 children.

Mary Bennett Jackson, 54, a Southeast Washington resident who also plans to attend, said she grew up near the plantation but knew little about the lives of the slaves.

A vocational development specialist, she plans to attend the reunion with seven of her eight children. "I just think it's really, really something that they're going back all those generations," she said. "I'll probably meet cousins I don't even know. It's a joy to go back."

"I think it's wonderful," agreed Nell R. Alexander, 52, of Largo, who also works as a vocational specialist. At least six of her family members are expected to attend, including a brother from Newark.

"My great-grandmother came from Somerset. Her name was Mary Riddick. It was always my understanding that she got pregnant as a slave but did not have any children in slavery.

"I can remember my mother saying that my great-grandmother knew nothing about how she was supposed to deliver this child. She had knives sharpened, thinking that it would have to be cut out of her."

Roy K. Spruill, a retired Baltimore policeman who works as a guard, said he wants to hire a bus to take him and 30 relatives to Somerset Place. He grew up on a farm near the plantation and remembers a two-story wooden slave house, which was torn down in the 1930s.

"They just had wooden pegs holding them together," he said. "And, the rumors were that when it rained the blood would reappear from the beatings in the old days."

From Redford's research Spruill learned, among other things, that his great-great-great-grandfather, Brittin Spruill, enjoyed a relatively prestigious position among slaves as a plantation hog feeder and had feet that measured 11 inches long.

Spruill said he is grateful to Redford for giving him a view of his past. "I feel that, as blacks, we stand out as first-class American citizens. We're getting recognized. I think her work should be honored, the way Alex Haley's was."

Redford's study was difficult, for there were few slave marriage documents and death certificates and no tombstones in the slave cemetery at Somerset Place.

Often, she depended on Somerset Place's inventories, in which slaves were listed as property, according to worth: "Ned Coakley, 59, (Infirmea Hernia) -- $50," and "King Jun, 12 (Blind and Useless) -- $00."

"It was like putting together a 500-piece puzzle," said Redford. "I got so excited when one of the pieces fit in.

"But, part of doing black genealogy is a matter of luck. If my ancestors had not been attached to a large plantation that maintained meticulous records, I would not have been able to do it."

Today, Somerset Place is a state historical site, visited by an estimated 9,000 tourists each year. The 14-room main house, which was ravaged after the Civil War, has been restored. There are few reminders of the slave population, which peaked at about 300 in the 1850s.

Redford said that Somerset Place's owners did not believe in separating slave families and did not discipline by force. Troublesome slaves were sold. "That wasn't that unusual in North Carolina," she said.

Also, she learned that many of Somerset Place's slaves were literate -- at a time when that was illegal. The slaves were able to earn money, including $20 gold pieces, which they could spend at a plantation store for shoes and clothes.

"That was unbelievable to me," she said. "There was more freedom of movement than I had imagined, particularly for artisans and skilled laborers."

There were terrible conditions in the plantation's rice fields, for some slaves apparently died there, she said. Quarters for the slaves were humble at best and usually cramped, with up to 15 people living in rooms of 324 square feet.

Redford's slave ancestors included Yaller Man Dave, a runaway who worked, among other things, as a driver and house servant. A great-great-grandfather named Fred Littlejohn was a plantation gardener.

"When the Union troops came, Fred was sent specifically to guard the orchard," said Redford. "But he left and went about one-quarter mile down the road to help the Union soldiers take the plantation's horses."

Redford said she tried not to become emotional while doing her study. But she feels strongly about the reunion, which will include African dances, the re-creation of a slave wedding, and an exhibit of slave artifacts.

For Redford the highlight will be the reuniting of long-lost relatives. "I'm just so excited about that whole possibility, about meeting all these really neat people," she said.