Joseph Davis (16 Jan 1814 - abt 1888), son of Reuben H. Davis and Eleanor Dean, married Mary Duling (10 Jun 1820 - 21 Mar 1864), daughter of William Alexander Duling (1779 - 1856) and Elizabeth Dean (1788 - 1837) (a sister to the aforementioned Eleanor Dean) on 11 Nov 1839 in Hampshire Co., Virginia. Yes, first-cousins married.
I have the daughter's name as Mary Ensley Davis and I don't know from where the Ensley name came.
William Alexander Duling (05 Apr 1779 - 10 Oct 1856) was the son of William Duling (27 Apr 1748 - 24 Nov 1839) and Sarah Ann Campbell ( 29 Sept 1757 - abt 1791). William Duling and Sarah Ann Campbell's children were: William Alexander Duling, Elizabeth Duling, Colin Campbell Duling, Edmund Duling, Sarah Ann Duling, and Zachariah Duling.