With race lending an unwelcome dimension to this year's presidential campaign, Annette Gordon-Reed's story of Thomas Jefferson's relations with his slave family, the Hemingses, reminds us in stark terms of slavery's tragic legacy.

		"THE HEMINGSES OF MONTICELLO" By Annette Gordon-Reead Norton ($35)

"It was a national tragedy -- the natural result of America's engagement with the institution of slavery, the doctrine of white supremacy and the nature of human frailty," she concludes.

That Jefferson, the Founding Father whose words "All men are created equal" established the moral core of the United States, could openly own hundreds of human beings while privately fathering at least seven children with an African-American woman remains one of the greatest ironies of American history.

Ignoring for a moment that the nation's third president "owned" these people, the Hemingses were his family and Sally his beloved companion for 35 years, the author proves with little doubt. Yet we cannot ignore Jefferson's full-fledged participation in slavery.

Gordon-Reed's previous book, "Thomas Jefferson and Sally Hemings: An American Controversy," is really the first volume in her study of life in Jefferson's Virginia. Here, she expands her research to include the biographies of Sally's family, starting with her mother, Elizabeth, herself the child of a white father and African mother who bore at least 12 children.

Six of those were fathered by white plantation owner John Wayles, whose "legal" daughter, Martha, married Jefferson -- and that marriage brought the Hemings family to Monticello.

Thus, the tangled web of interracial relationships was woven and rewoven every day to make the culture of the Southern "slaveocracy," with its own set of bizarre laws that were as hypocritical as they were inhumane.

In Virginia, sexual relations with slaves were illegal yet accepted and commonplace.

Gordon-Reed attempts to tally up the human toll of this hypocrisy on the children of these illegal unions, particularly on the Hemingses, some freed by Jefferson, some sold to pay his debts, others lost to history.

The widowed Jefferson was 30 years older than the teenage slave when they began their intimate relationship, most likely in Paris, where he served as U.S. envoy. He never remarried yet kept Sally in Monticello for the rest of his life. Her brothers were also close to their owner; James was Jefferson's chef in Paris, for example.

Gordon-Reed contends that while in France, a country where Sally could gain her freedom, she and her famous lover made a pact: She would return with him to America if he agreed to free their children.

Jefferson later did free them, although Sally was never given emancipation.

Gordon-Reed, a legal scholar, has written a history of several levels. She transforms her research drawn from the existing records -- letters, Jefferson's "Farm Books," contemporary accounts and the trove of historical studies of the man -- into a fully realized picture of the times. That's the accomplishment of the book.

However, faced with a scarcity of reliable documentation from the enslaved people of the time, she speculates, makes assumptions, plays psychologist and at times sounds like Ann Landers.

"Some trials are more difficult than others, and realizing that things could always be much worse often shapes one's response to an unhappy situation," she comments about the life of Jefferson's daughter, Martha, whose 12 children were the result of "the lack of a culture of and access to birth control."

In fact, there was simply a lack of reliable contraception, period, in 1790.

Martha's husband, Thomas Mann Randolph, is described as an abusive, violent man, yet without any proof, Gordon-Reed assumes that his "struggles with depression and feelings of inadequacy could likely be treated today with medication and/or therapy."

Or neither? How about just a kick in the pants? Historians simply should not jump to such meaningless conclusions.

The preservation of property and family was often the reason for marriages in 18th-century Virginia, until "love began its ascendance as the primary purpose for unions between males and females," she adds at random.

Then, there's Gordon-Reed on her approach to research:

"Following the trajectory of Hemings' life, and taking her seriously as a person, requires one both to notice when the trajectory veers and to look for an explanation for the change of course."

There you get both a sense for her lawyer-like prose and tendency to state the obvious, something she does frequently. That combination saps the spirit and pertinence of her industrious research into the still-uncovered lives of America's enslaved peoples.

Despite Gordon-Reed's clumsy presentation, her work illustrates why the poisonous fallout of that heritage continues to fall across the land.