They released the findings in advance, they waived the usual embargo on newsworthy articles, and they stood by as one of the two researchers said that it all went to prove that President William Jefferson Clinton's liaison with White House intern Monica Lewinsky was not such a deviation from the norm after all: even the revered author of the United States Constitution had had his peccadilloes.
What neither editors nor authors apparently anticipated was that their learned article might succeed where Alex Haley's Roots, Steven Spielberg's Amistad, Oprah Winfrey's Beloved and a spate of books and documentaries have failed - in pushing slavery to the fore and goading whites as well as blacks to talk about it. But once the immediate excitement over the parallels between Thomas Jefferson and William Jefferson Clinton had ceased to titillate, that is precisely what happened.
For many black Americans, the likelihood, based on DNA evidence, that Jefferson was the father of Sally Hemings's son, Eston, born in 1808, was not news, but vindication. "Everybody knew that already," one Washington teenager said. And his teacher added: "Look at the black people in this class. We are the colour of the rainbow. Our ancestors didn't come over from Africa this way."
For blacks, the question - asked with some resentment - was why Jefferson's liaison had dismissed for so long. Patricia Williams, a law professor at Columbia University, was moved to ask: "Why was there such denial for so long among historians and many whites?"
Such direct questioning forced a response. Some historians mounted a hasty exercise in damage limitation. Gordon Wood, a Brown University historian, was quoted as saying he had thought Jefferson "too uptight and puritanical to mix with a slave". He added: "I don't think the people who doubted this did it out of racial superiority ... We all knew that slave owners were having sex with their slaves, but there was a feeling that Jefferson was not doing that."
Others, however, confirmed blacks' worst suspicions. A white visitor to Washington, interviewed at the Jefferson memorial, said it was "a sad day for the country". To which Tim Hughes, a local black resident who claims to be a Jefferson/Hemings descendant, responded: "I do not believe it was a sad day for her because she discovered Jefferson fathered a child out of wedlock ... [but] because he did this with a black woman and therefore reduced his humanity ... the black woman to her was something less than human."
What the DNA findings exposed was a gulf in historical perceptions that many found shocking. Yet the fact is that, whatever they were taught at school, blacks and whites view America's history differently, especially its early history.
The white, establishment version is that the founding fathers, including Jefferson and George Washington before him, were fine upstanding figures in every respect, including the moral one.
Anything contrary is largely dismissed - despite, in Jefferson's case, a swirl of rumours during his lifetime. Even the fact that America's first presidents owned slaves has been played down almost to vanishing point.
Among blacks, slavery - and white negation of it - are taken for granted. And what is passed down from generation to generation is not only the opinion, but the assumption, that as slave-owners, America's first presidents slept with their female slaves. The very question, much asked in the wake of the Jefferson revelation - was it rape or affection? - is tartly dismissed. "He owned her. At any moment he could sell her," said Prof Williams.
Many blacks know they have white blood in their line. They always believed Jefferson fathered children by Sally Hemings because they believed their fellow blacks who claimed Jefferson as an ancestor and bore his name.
When the DNA evidence came through, the eye-opener was not that Eston was found to be a likely descendant of Jefferson, but that another child of Hemings, Thomas Woodson, whose descendants had also claimed presidential ancestry, probably was not. That appeared to demolish a cherished legend: that Jefferson had taken Sally Hemings to his bed when she was only 14 years old.
There are those on both sides of the racial divide who hope that the new evidence will bring black accounts of history more acceptance and that white and black alike will find it easier to acknowledge a common history. Some feel that blacks will take more pride in their past as a result.
But already a new and potentially inflammatory dispute is brewing. The Monticello Association, the group of (white) Jefferson descendants which owns and runs the graveyard at the late president's estate, is split about whether future descendants of Hemings might be buried there.
Raw and bitter as it is, the Jefferson controversy has hit a nerve. A Thanksgiving holiday phone-in had an abundance of callers. And even a month after the initial revelation, black resentment still came through. One caller was a black woman who had visited Monticello as a tourist and noticed that a back staircase that was supposed to have led into Jefferson's bedroom was not there.
It had been removed, she was told, during routine restoration and refurbishment: a sort of architectural revision of history. "Maybe," ventured the caller hopefully, "they will build the staircase back?"