A history professor who peeked into the wrong Library of Congress file has stumbled onto the records of a sensational, long-forgotten 18th-century trial alleging the attempted debauchery of George Washington's sister-in-law by a prominent Fairfax County cleric who later became the first president's physician.

The records, which document the only full-scale ecclesiastical trial ever held in Colonial Virginia, paint a complex portrait of Ann Fairfax Washington, first mistress of Mount Vernon, who according to the testimony was either the adolescent prey of a lascivious parson or an 18th-century Lolita tempting an upright clergyman to sin.

The testimony, replete with references to exhibitionism, fondling and even sexual play with vegetables, gives a rare look into the private lives of some of the most famous families in American history.

"This was no small event," said George Mason University history professor Peter R. Henriques the other day, proffering photocopies of the faint, quill-penned documents in his Fairfax County home. "It was widely discussed in Maryland. A Philadelphia newspaper tried to purchase the story. The governor of Virginia personally intervened in the trial."

But in a particularly Virginian fashion, Henriques says, the aristocratic families involved combined to keep a highly public scandal entirely out of the public press and ultimately have it all but erased from history.

How Henriques happened on the story is a textbook case in the serendipity of research. In quest of information 18 months ago on an obscure neighbor of George Washington named Capt. John Posey, Henriques was looking for a well-thumbed primary source document for the early history of Fairfax County written by a Rev. Charles Green.

Not knowing the document was in a separate file, Henriques asked for "the Rev. Charles Green papers" and soon found himself puzzling over an exchange of obviously angry letters, plus records of some sort of legal or semi-legal proceeding. At the center of the correspondence was George Washington's older half-brother, Lawrence.

"It was clear that Lawrence Washington was making serious accusations against the Reverend Mr. Green," Henriques said. "But the documents were difficult to read and referred to others that weren't there. It took me quite a while to realize what I had, and even more to piece the whole story together. Even then I assumed others must have come upon it years ago."

When he checked with historians at Mount Vernon and Colonial Williamsburg, however, "nobody knew anything about it," and he began to realize what a bombshell he had.

"In some ways it's a story out of today's headlines," he said. "The issues it raises are very much with us still."

As told by Henriques, who is writing a scholarly article on the trial, the story begins in 1736 when George Washington's father, Augustine, nominated as rector of Pohick Church and what was then known as Truro Parish the Rev. Charles Green, 26, a headstrong, Oxford-educated clergyman who had arrived in Virginia only three years before.

Green, who was also a physician, allied himself with the local gentry and quickly became close friends with William Fairfax of Belvoir, one of the wealthiest and most influential men in Virginia. Though 20 years older than Green, Fairfax admired the young pastor immensely, naming Green and his wife, Mary, godparents to several of the Fairfax children.

Also friendly with the Fairfax family was Lawrence Washington, who in 1742 returned to Virginia from the Caribbean after fighting against Spain in what became known as the War of Jenkins' Ear.

While his younger brother, George, was still a lad, Lawrence had been schooled in England, had won praise for his military efforts, and had achieved considerable reputation and influence by the age of 25.

Now establishing himself as a planter on the estate he named Mount Vernon, Lawrence found his attentions falling upon William Fairfax's teenage daughter, Ann, perhaps the most eligible young woman in the colony.

No portrait or physical description of Ann Fairfax has survived, but "she was clearly an attractive, if not flirtatious, girl," Henriques said.

Ann, however, was also a young woman with a clear need for affection. Her mother had died when she was a very young child, and her stepmother, Deborah, a strong-willed woman of keen mind and education, capable of penning French epigrams and Socratic quotations, "perhaps overawed her," Henriques said. As Deborah Fairfax gave birth to four new children, Ann evidently felt increasingly ignored within the Fairfax family.

As compensation she had turned for companionship to Green, whom she first met when she was a child of 6 and soon knew well as a frequent visitor and family friend. Exactly what went on between them as the years progressed remains unclear, Henriques said, "but there was clearly at least {during her girlhood} the sort of innocent horseplay adults have with children" plus "times when she would sit on his lap, hug him and rub his neck in an affectionate manner."

She also, Henriques said, found in Green a confessor and confidant to whom she could pour out her heart about her "ill-usage" by her stepmother and her difficulties within the Fairfax family.

In March 1743, however, there was a rupture in the relationship between the Green and Fairfax families, the reasons for which were not made public.

That July Ann married Lawrence Washington. She was 15.

Two years later, his public stature now enhanced by his roles as both adjutant general of Virginia and a member of the House of Burgesses, Lawrence Washington wrote the Rev. William Dawson, the bishop of London's official representative in Virginia, demanding the removal of Green as rector of Truro Parish. His accusation: Green had been guilty of frequent attempts to "debauch" Ann Fairfax Washington in the years before her marriage.

Despite the shocking nature of the charge, Washington did not ask that Green be defrocked. He said that to avoid a public scandal he would be satisfied if Green were just sent to some distant parish.

Green, however, vigorously and indignantly denied Washington's accusations, refused to leave his post and promptly filed suit against his accuser for slander. Washington, in turn, demanded a full-scale ecclesiastical trial, promising to "purge the church of so unworthy a member," a "vile rogue" who by his immorality had brought religion into contempt.

The resulting trial was evidently a public sensation. It began on Nov. 6, 1745, in Williamsburg in the Chapel of the College of William and Mary, where Dawson was pastor and where he heard the evidence together with two other clergymen. Though outsiders were barred from the proceedings, rumors of the testimony spread quickly, augmented by publicly circulated petitions demanding Green's ouster signed by such prominent members of his parish vestry as John Carlyle, master of Carlyle House in Alexandria. Not content with portraying the clergyman as a wanton seducer, the petitions accused him of everything from neglect of duty and disturbing the peace to land fraud and cattle theft.

The ecclesiastical proceedings followed a form prescribed by the bishop of London, with each side presenting a list of witnesses to be heard and cross-examined. Each witness's testimony before the judges was summarized by an official recorder, then corrected and signed by the witness.

"Unfortunately, Ann Washington's deposition did not survive," Henriques said, "but enough others have survived to give a pretty good idea of the evidence."

The most damning prosecution witness, he said, is Ann's stepmother, Deborah, who portrays Green as a ruthless pedophile betraying the trust of an innocent girl. When Ann was only 9 years old, she says, Green stood her on a chair, thrust his hands up her clothes and pushed himself against her. At age 10 or 11, while caring for Ann during her parents' absence, Deborah Washington says, Green carried the child into a fodder shack and exposed himself to her. Another time, while playing hide-and-seek with the Fairfax children, she said, Green found Ann under a bed, pulled her atop the bed and "pushed himself against her in an indecent and immodest manner."

Green's most serious attempt, Deborah Washington said, occurred when Ann was 14 and visiting the Green home. The pastor suggested they go for a walk. Passing a pile of boards, Green pulled one off the stack, threw Ann upon it and pulled up her clothes. He then "uncovered his nakedness" and fell upon her, stopping only when a servant passed nearby and Ann threatened to scream.

Ann was ashamed to confide the incident to her stepmother, according to the evidence, and first told a servant and then her aunt. The horrified aunt immediately told Deborah Fairfax, who relayed the information to her husband, who promptly wrote Green, "Your crimes are discovered!" and broke off all correspondence with the minister.

Deborah testified that at this point Green acknowledged himself guilty of "an indiscretion," but protested that no harm had come from it since Ann was still a "virga intacta." No such letter was introduced in the trial, however. The Fairfax witnesses said they burned it in an effort to keep the incident quiet and not damage Ann's reputation and chance for a good marriage.

Yet Henriques said the case against Green is clouded by an increasing, and apparently separate, hostility to Green by Deborah Fairfax during the period, hostility apparently stemming from a dispute over a family will. Ann's story, he said, could have been colored by that hostility.

Then too, he said, 32 pages of notes analyzing the evidence, penned by "an extremely perceptive witness to the court proceedings who unfortunately remains a mystery," shows Ann was "very outgoing, even forward" in her relationship with Green, not only sitting on his lap at times but occasionally asking him to lace the stays of her corset. Green's sister-in-law, a major defense witness, testified that the night before the final break between the families -- and apparently after the alleged rape attempt -- Ann "kissed and patted and embraced him until he blushed."

These would not appear, Henriques pointed out, to be the actions of a girl terrorized by molestation. They seem instead, he said, those of a young woman discovering her sexuality. Her accusations against Green, he said, might have stemmed from her discomfort with that discovery and the frightening reactions her behavior sometimes provoked. The judges, he said, clearly reached the conclusion that Green was innocent of anything serious.

Since Green's only possible defense was to attack the testimony and character of Ann Fairfax, however, "you have to wonder why Lawrence Washington chose to put his wife through this ordeal," Henriques said. Green's sister-in-law, Mary Bolan, was asked what she knew of Ann's "loose behaviour and lascivious actions in bed." Another witness indicated that Ann's brother had seen her doing "something improper with radishes," a vague reference, Henriques interpreted, "to some kind of masturbation or sexual stimulation."

After a week of hearing such evidence, the court adjourned until the following April when closing arguments were scheduled. Before that time, however, Gov. William Gooch, a close friend of Lawrence Washington, clearly distressed at the turn things were taking, personally intervened in the case. As both an extremely popular governor and secular head of the Anglican Church in Virginia, he was ideally positioned to do so.

Under the settlement he worked out, Green dropped his slander suit against Lawrence Washington and also paid the not inconsiderable costs of the trial, which normally would have been borne by the loser.

"But on the key point," Henriques said, "Green won. He was not removed as the rector of Truro Parish. In fact, he stayed there the remaining 20 years of his life, repaired his obviously damaged reputation, and died a rich and respected clergyman. George Washington employed him as a physician and became his friend. The families involved gradually healed their differences and seemed determined to put this behind them."

The process may have been eased by the sudden death of Deborah Fairfax the year after the suit -- she was not yet 40 -- and of Lawrence Washington of tuberculosis five years later at the age of 34. "It's easy to forget how hard and short people's lives were then," Henriques said.

But perhaps the true measure of the suffering endured in those days was felt by Ann Fairfax Washington. Five times between her 15th and 24th birthdays she gave birth only to watch her child die a short time later. None lived past the age of 4. Only months after her husband's death she married George Lee -- a distant antecedent of Robert E. Lee, and with him had three sons. She never, however, lived to see them grown. She was dead by the age of 33.

"You know, a feminist historian could have a field day with this story," Henriques said. "You can use it to prove anything you want about 'the victimization of woman,' 'the history of sexual harassment' or whatever."

But for him, he said, the true fascination of the story is the flesh and blood it puts on those dusty names from two centuries ago, and how much closer it brings their lives. "These were obviously very strong and vital people," he said, fingering the photocopy of a fading letter. "They were all caught up in very human situations of the kind we see very much today. And most of them died so very, very young."