I think you are one of ours;)Nancy Isabella Calhoun was married to Andrew J. Dorsey in Pickens County, SC May 15, 1849.
While we have no one document saying that Andrew was the son of William and Martha Kelly Dorsey, we are quite certain that he was.William Dorsey was the son of John H. Dorsey who moved through Lincoln, Burke, and Macon Counties in NC in the early 1800's.He moved to Pickens County, SC sometime in the 1840's and died there in 1852.
DNA testing has shown that John Dorsey was either the son or grandson of Andrew and Patience Dorsey who moved from Maryland to Rowan County, NC in the 1760's.As a part of a larger Dorsey DNA study, we have a small DNA project going on this family.You can read about it at http://www.contexo.info/DorseyDNA/Results.htmhttp://www.contexo.info/DorseyDNA/Results.htm.Near the top of the page is a link to "Andrew Dorsey Line Analysis".In addition, you can read how we used DNA to show that our gggrandfather Harvey Kelley was really your Andrew's brother Elisha Dorsey. http://www.contexo.info/DorseyDNA/HarveyKelley.htmhttp://www.contexo.info/DorseyDNA/HarveyKelley.htm
Eventually, Andrew left Nancy Dorsey and went to Blount County, TN where he took another wife and had more children. Interestingly, the University of Tennessee has some old photographs of Andy Dorseys cabin and some family members in Blount County in a private collection there.It is possible to order copies.
If you will contact me privately at Dorsey@Contexo.info, I will put you in touch with other descendents of Nancy and Andrew Dorsey and send you more information about the Dorsey family. Your Mary is with her mother in Jackson County, NC in the 1870 census and with her husband Cornelius in 1880-also in Jackson County.