How many kids did Thomas Jefferson have?

President Thomas Jefferson had six children with his wife, Martha. The eldest, Martha, and the fourth born, Mary, were the only two Jefferson children that survived to adulthood.

Thomas Jefferson married Martha Wayles Skelton on January 1, 1772. He was married to his wife for ten years before she died at the age of 33 after a long illness. After her death he never remarried, however it is alleged by many historians that he carried on a relationship with Martha's half-sister, a slave named Sally Hemings. Hemings had six children, all of which are suspected of being Jefferson's. Of his known children with Martha, only his eldest daughter outlived him.