For most Philadelphians, the name Chew is not particularly evocative.

Perhaps it conjures a hazy sense of Founding Fathers living in gentility and getting a street named after them for their efforts. Some may be aware that Cliveden, the formidable stone mansion on Germantown Avenue where the Battle of Germantown was fought in 1777, was built by Benjamin Chew in the 1760s and served as a country retreat.

That's probably about it. But such haziness soon may be dramatically dispersed.

In the last two years, thanks to laborious research and the pack-rat proclivities of generations of Chews, a vivid and dramatic family story line has been emerging - of slaveholding and slave dealing; of wealth built on plantations throughout Delaware and down into Maryland, worked by countless enslaved Africans; of enslaved laborers who attacked overseers to protect black families; of slaves associated with the Chinese opium traffic at the behest of Chew masters; of possible sexual abuse; of escapes; of relentless pursuits and abiding paternalism.

"This place is exploding," said curator Phillip Seitz, referring to the wealth of Cliveden information being uncovered. The Chews apparently saved everything, and now the detailed records of the buying, selling, and leasing of slaves are coming to light after being tucked away in boxes and cabinets for, in some cases, more than two centuries.

It is a rich, complex, sometimes nasty story of the birth of a nation, and Cliveden, often viewed as remote by its neighbors of color, is arguably at its center. Now the staff of the mansion, owned by the National Trust for Historic Preservation, has thrown itself into recounting this emerging multiracial, multigenerational drama.

"The Cliveden guides are not telling the story of the Chew slaves . . . and we'd like to rectify that," Cliveden executive director David W. Young told a recent meeting of community members, historians, and educators gathered to discuss the direction of programming at the mansion.

"The board of directors wants the changes made," Young continued. "They want the walls to come down. They want the doors to open. We have this moment" - a moment that falls within a period of intensifying interest in other Philadelphia sites that are part of the slave narrative, from the President's House slave quarters to Mother Bethel A.M.E Church, the denomination's foundation church and a major Underground Railroad way station.

Seitz, who has immersed himself in the sea of Chew family records now being organized and indexed at the Historical Society of Pennsylvania, said it is well known that the Chew family held Africans in bondage.

After all, he notes, Benjamin Chew, Pennsylvania's chief justice in the years before independence, was the owner of Richard Allen, selling him and his entire family to a Delaware neighbor in 1766. Allen eventually purchased his freedom and went on to found Philadelphia's Free African Society and the African Methodist Episcopal Church.

What is new, says Seitz, is the sweep of the Chew ownership that is becoming apparent as records are reviewed.

Samuel Chew, father of Benjamin, was "the biggest slaveholder in the province of Delaware," Seitz said. At the time of his death in 1744, he held about 60 slaves on three properties in Delaware, including Whitehall Plantation, nearly 1,000 prime tobacco-growing acres in Kent County.

Generations of slave families are recorded in Chew ledgers. Births, marriages, deaths, sales and rentals are logged in property inventories and estate records.

"Slavery was the family business," Seitz noted, and as such required as much attention from the businesslike Chews as every sale of tobacco and purchase of corn.

But in addition to the unusually detailed records of slaves - more and more of which are emerging as the extensive records of Chew holdings in Delaware and Maryland are examined for the first time - the Chew papers contain countless letters and copies of correspondence.

The letters put blood and heart onto the abstract, skeletal ledger lists.

For instance, Joseph Porter, Whitehall overseer, wrote Benjamin Chew Jr. on Jan. 14, 1800, to describe "some disturbances between me and the young hands that is Jim and Yarm."

Porter's wife, it seems, had sent Nan, an enslaved child, for some thread. Nan dawdled and ended up being slapped by Mrs. Porter.

Jim intervened, telling the woman "she should not touch" the child. This minor conflict escalated as Mrs. Porter ordered Jim to stop his "sas" and leave the house.

"He told her he wold not," Porter writes. "The hours was more his than his & he stay as long as he pleased & told hir he was as good as hir . . .. So I went out & I raised my Cain to strike him & he amediately spring at me & tried to throw me."

The scuffle spewed out into the yard, at which point Yarm, another enslaved worker, "picked up a large stick" and "said If I touched Jim he'd split my Brain."

The standoff ended with Jim and Yarm running out of the yard and eventually being whipped for their transgressions. That was not the end of it. Yarm continued to defy Porter, the next time threatening him with an ax. Porter sought assistance in that conflict. And Yarm then ran after him "and humbled himself & promised me his good behavior & I forgave him & he is now at his work."

Porter promptly turns his attention to a discussion of the wheat crop.

The letters also offer glimpses into the story of David, rented out to Benjamin Chew Wilcox, American consul in Canton and a player in the Chinese opium trade. David voyaged four times to China - perhaps as part of drug trafficking; Harry, another family slave highly regarded by the Chews, attended Baltimore-born Elizabeth Bonaparte, first wife of Napoleon's brother Jerome. Harry established himself in the Bonaparte entourage and then took the opportunity to disappear into freedom.

Cliveden staff members have begun exploring the former Delaware and Maryland Chew properties, though not all the properties have been located and identified. Seitz and John Reese, a Germantown resident who has worked at Cliveden, recently visited Whitehall. The plantation, located on a crook of the Leipsic River, looks much as it probably did in 1800, Seitz said. But it was the feel of the place that affected Reese.

"The first thing that hits you when you see the vastness of his 1,000 acres is that 70 people worked this with no modern equipment," he told the group assembled to discuss Cliveden. "The second thing that hits is the emptiness. There is no place to go.

". . . The third thing that hit me as a black person is when we went to the little dock, that little dock where all the products came in. That was a very emotional experience. All this labor. All this time. All this sweat. And all the products of this labor get shipped, and you don't get a cent."

John Chew, a professional photographer from Wayne who represents the family on Cliveden's board of governors, also has visited Whitehall and felt its power.

"I was able to look over the fields where black men had worked in bondage and slavery, and for the first time in my life I could feel it - the burden and sorrow that a black man might feel about his history," he said.

For the living family members, the ever-expanding Chew narrative "brings detail and some humanity to the story. I think we're all more or less on the same page, and that is, that the truth is important and knowledge is something always to be sought."

The Chew papers have not been completely indexed, and the extent of the holdings, particularly in Maryland, is not yet clear. About 200,000 documents went to the historical society when the National Trust took over Cliveden in 1972. But papers continue to turn up - at least 70 shelf feet of documents have been found since the initial cache was turned over to the historical society two decades ago. More vivid stories are certain to emerge from the trove.

One thing that's clear from the preliminary discussion of future Cliveden programming is that historians, educators, and community residents all want these stories told. The institution of slavery, they agreed, was key to building wealth in Philadelphia, much as it was in Virginia.

"It's not hard to free up your time when you have 70 people working for you for free," said Reese. "The standard thought process in the North is that slavery was down there. . . . But it wasn't just down there. There are things that took place here in Pennsylvania - not on the same scale, but most people don't know the part slavery played in building the South and the North."

Contact culture writer Stephan Salisbury at 215-854-5594 or ssalisbury@phillynews.com.