Jefferson DAVIS had no surviving sons and only one of his daughters married. His only descendants surnamed DAVIS would be the children of his grandson, Jefferson Addison HAYES, who had his surname legally changed to DAVIS. With only four grandchildren surviving to marry and have children, descendants of Jefferson DAVIS are a rare commodity.
Note that the four Jefferson DAVIS grandchildren lived well into the 20th Century. If you are alive today and your parents or grandparents are not among the above, then you cannot possibly be descended from Jefferson DAVIS.
http://dgmweb.net/FGS/H/HayesJoelAddison-MargaretHowellDavis.html