If you are referring to Isham Walker who married Mary Carter he is in Group 35 of the Walker DNA Project. None of the people who match him have pedigrees that would indicate that his parents have been found. You can see the DNA results at the following website.
Barbara Walker Good BWGood@aol.com
Walker Surname DNA Projecthttp://www.familytreedna.com/public/Walker
DNA Project mtDNA Results