In a basement room in the new Fairfax County Courthouse yesterday, local historian Edith Sprouse tended to a table piled high with crumble-thin documents and quill-penned letters. The thousands of pieces and papers of Fairfax County history, on public display for the first time, had been gathering dust for as long as 200 years in the attic of the old courthouse nearby.

The creased and faded documents were the written confirmation of lives long since passed: money judgements, missing deeds, insurance policies, school and birth and death and marriage and military and tax records.

There was a 1746 bill of sale for 226 acres of county land, an 1800 architectural drawing of a house on Prince Street in Alexandria, rendered in delicate shades of pink, and a long-missing county minute book from 1813, wherein the day-to-day accounts of the county's business were recorded. There is a petition from a man named Gartrel who had been seized, blackened with printers' ink and paraded on his horse through Alexandria because he had voted for Abraham Lincoln. He wanted a court award of $20,000 from his assailants.

"It's a very exciting find, an important find. We still don't know what's here, but with all these records, we will be able to fill in a little more about the history of the county," said Sprouse, a member of the county history commission.

According to Circuit Court Clerk James Hoofnagle, the county has known for years that thousands of documents, "several truck loads," were gathering dust in the old courthouse attic. Renovation of that building, due to begin soon, made it necessary to remove the documents. Two months ago, the oldest documents, those dated before 1904, were found.

"What we have here," said Hoofnagle, "is the history of Fairfax County, more complete than ever before. We don't know if it will change what we know about the history of the county. I doubt that it will. But we certainly will know more than before."

Constance Ring, the county archivist, said the first step the county will take is to wrap all the documents in tissue, then store them in acid-free envelopes in acid-free boxes to keep them from decomposing any further. The long-range plan, she said, will be to index and microfilm all the documents.

"If we had an army of people to do the job it might take us a year," said Ring, who will supervise the project. "Without that, it may take us through my grandchildren's time."

In the meantime, the pleasure of the documents is in the browsing. One learns that it cost $6 to board a pauper for a month in the early 1800s and that there was something called the Lunacy Board at about that same time, which authorized payments of $5 to doctors for examining people thought to be insane.

Also in the pile is the testimony of one Mrs. Forrest Olden, written in her own hand during her husband's trial in 1864 for the murder of a Confederate soldier. Mrs. Olden wrote that she was asleep in bed one night when she heard someone walking up the stairs. He came to the bedside, she wrote, pistol in hand. "He told me what he wanted. I told him to come back the next night." When the soldier came back the next night, Forrest Olden shot him, according to Mrs. Olden's testimony.

In the genteel manner of the 1872 Fairfax County courtroom, a note in another case from the jury to judge, in exquisite script, reads: "King William the third said my kingdom for a horse. We the jury feelingly remark we want something to drink."