Sally Hemings in The Jefferson Presidency
Sally Hemings (1773–1835) was a slave at Thomas Jefferson's Monticello plantation with whom Jefferson almost certainly maintained a long sexual relationship.
It's believed she was the daughter of John Wayles, a white plantation owner, and his slave, Betty Hemings. John Wayles' white daughter, Martha, married Thomas Jefferson in 1772, which meant that Jefferson's wife and his slave mistress were likely half-sisters.
A companion and maid to Jefferson's daughters, in 1787, Sally accompanied nine-year old Polly Jefferson to France, where Thomas Jefferson was serving as United States minister. After returning to Monticello in 1789, she labored as a house servant and seamstress. Between 1795 and 1808, she bore six children who were light-skinned and reputedly bore a striking resemblance to Jefferson.
DNA tests published in 1998 suggested that Jefferson was almost certainly the father of her youngest child, Eston Hemings, and probably the father of the other five as well. Jefferson's records reveal he was present at Monticello nine months prior to the birth of all six. The same records don't suggest that a male relative, with similar DNA, was present at these times.
Four of Sally's children survived into adulthood and all were eventually freed by Jefferson, two of them in his will. No other group of slave siblings at Monticello was freed by Jefferson. Sally wasn't freed in Jefferson's will, but Jefferson's white daughter, Martha, permitted Sally to leave the plantation and live with her sons after Thomas Jefferson's death.