I think I just responded to this on the rootsweb Mobley list.
But, for the people that come to this board....
First, my Richard S. Mobley was the son of Richard H. Mobley and Martha (White) Mobley.He was born in Georgia according to the 1870 census.(By 1870 Martha was a widow, but sibling group indicates it is the same family.)
Second, the birth year for your Richard S. Mobley is within a year or two of the birth year for my Richard Hill Mobley, who seems to have been born in North Carolina or South Carolina.