Thank you for your reply to my posting.Your James Madison Murdock b. 1818 appears to be too young to be the father of the subject Mary Murdock, who married John Griffin in Stewart Co., GA, on 13 Jan 1848, and was probably b. ABT 1828 or earlier.Lazerous (Lazarus?) Murdock b. 1850 in Stewart Co., GA, fits far better as the son of your James.
I have no proof that the subject John and Mary Griffin are even the parents of my ancestor, which is why I was looking for somone who had verified info on some or all of their children.
I'm content to wait.My tedious searching for John & Mary Griffin, with their unbearably common names, produced no hits in counties of the 1850 GA census and the 1860 GA & AL censuses.