President Thomas Jefferson married his third cousin.
Anonymous/AP
President Thomas Jefferson married Martha Wayles Skelton Jefferson, who was his third cousin, according to Forbes. The two wed in 1772 after she had been widowed by her first husband, according to White House records. She died in 1782, and Jefferson swore to her on her deathbed that he would never marry again, according to US News.
Jefferson would later become widely known for fathering children (via rape) with Sally Hemmings, an enslaved woman he owned who was Martha Jefferson’s half-sister. At the time, his contemporaries wrote he “kept, as a concubine, one of his own slaves,” according to POLITICO.
