JenniferM is my cousin, so I'm sure she would not mind if I responded to your posting. Most of our family comes from the Horry Co., SC area. We have also traced back a little farther to Bladen and Columbus Co., NC.
The James S. Murdock in our family was married to Jane. In the 1880 Horry County Census their family is listed as follows: James 33, Jane 23, Thomas 6, Alexander 5, Sarah R. 3, Elizabeth 1. I also know that there were a couple of other children, Bessie and Maggie.
James S.'s parents were Joseph and Elizabeth. If you feel that this is of any help or would like to compare some more notes, post again or e-mail me and we'll sway stories.