Adrian, Thank you, but this Mary McDoniel, daughter of Wm. C. and Mary McDoniel, born in 1820, CANNOT be the Mary McDoniel that married Ewin/Ewing Clark on 08 March, 1859. To quote directly from the marriage certificate, "..... Ewin Clark of said County, aged fortythree years and Mary Mcdoniel of said County, aged twenty six....." and, according to 1860 for Independance Co., Ark., ".....Mary, age 26, born TN. ....."
This would put the Mary McDoniel who married Ewin/Ewing Clark as being born about 1834. Thus, I believe she would either be a grand-daughter or daughter-in-law to Wm. Chapman and Mary McDoniel; IF SHE IS PART OF THIS FAMILY. So far, I have not found any other family with the same "McDoniel" spelling. I also suspect she was married to a McDoniel (then widowed or ?) based on her age (wasn't '26' sort of 'old' to be getting married in the 1850's?) and word from my Clark relitives that there were some McDoniels around, but they didn't recall how they were related or socialize much (if at all) with them.
Any help with this brickwall of mine is greatly appreciated. Ewin/Ewing and Mary (McDoniel) Clark are second great-grand parents of mine. Thanks!