In January, 2000, the Thomas Jefferson Memorial Foundation reported its findings on the Hemings/Jefferson controversy: did Thomas Jefferson father the children of his slave, Sally Hemings?
Their answer: the likelihood that he did is strong -- stronger than any alternative possibility.
A stellar committee of historians, scientists and Jefferson scholars examined the available evidence and concluded that Jefferson fathered Eston Hemings and perhaps the other children of Sally Hemings.
Oral history in the families of Thomas Woodson and Madison Hemings, and more recent genealogical research in the family of Eston Hemings, include claims to descent from Sally Hemings and Thomas Jefferson.
DNA tests on male-line descendents of Jefferson's grandfather, of Jefferson's Carr nephews, of Thomas Woodson and of Eston Hemings were released in November of 1998 in the scientific journal Nature. These results indicated that Eston Hemings was almost certainly descended from the Jefferson male line, that Thomas Woodson was not, and that neither Eston Hemings nor Thomas Woodson were descended from Jefferson's Carr nephews, the "usual suspects" named as the father of Sally Hemings' children. Because there are no male-line descendents from Madison Hemings, tests were not applicable to those claims, and the DNA tests don't directly provide any evidence or counter-evidence.
The whole controversy illustrates some basic principles of the study of history, and particularly a few issues which are often seen when one looks at history through the perspective called "women's history."
"Women's history" is not simply the study of women in history -- it is also a perspective that says that examining women's roles and women's contributions often brings to light conclusions that otherwise might have been missed.
All this concern over DNA tests of male-line descendents illustrates a simple sex-based principle of history and genealogy, best summarized by the old saying about the difference between knowledge and belief: "Mrs. Jones knows she has a son, and Mr. Jones believes he has a son."