One of our most popular blogs was on descendants of Jefferson Davis (Jan 9) so I thought you might also be interested in his genealogy. Now, a disclaimer, the following is according to the Internet, not facts that I have personally checked.
According to what I read, Jefferson's great-grandfather, Evan Davis, Sr., was born before 1695 in Wales, and died between 1743-47 in Philadelphia, PA.He was married to Mary, also born before 1700 in Wales. She died in 1758 in Philadelphia.
Their son Evan Davis, Jr. was born in 1729 in Phil. and died bet. 1756-62 in GA. He married Mary Emory who married first Mr. Williams, and second Evan Davis, Jr.
Their son, Samuel Emory Davis was b. 1756, GA and d. 1824, Woodview, MS. He married Jane Cook, daughter of William Cook. She was b. 1761 and d. 1845. Jefferson Davis was their 10th and last child. He was born in Fairview, KY in 1808 and moved with the family to Woodview, MS at a very young age.
Eight of his brothers and sisters had surviving children but only two of his siblings left descendants named Davis beyond one generation. So (the Internet tells us) if your surname is Davis and you have traced your Davis ancestry back into the 1800's without connecting to the grandsons of Samuel or Lucinda Davis, its probably time to bury the family legend of being cousins of Jefferson Davis!