Davis was born on June 3, 1808 in Christian County, Kentucky, the last child of ten of Jane (née Cook) and Samuel Emory Davis. Both of Davis' paternal grandparents had immigrated to North America from the region of Snowdonia in the North of Wales; the rest of his ancestry can be traced to England. Davis' paternal grandfather, Evan, married Lydia Emory Williams. Samuel Emory Davis was born to them in 1756. Lydia had two sons from a previous marriage. Samuel served in the Continental Army during the American Revolutionary War, along with his two older half-brothers. In 1783, after the war, he married Jane Cook (also born in Christian County, in 1759 to William Cook and his wife Sarah Simpson). Samuel died on July 4, 1824, when Jefferson was 16 years old. Jane died on October 3, 1845.