Hi there.
This post is now several years old, but maybe you still need help.
James Walker was born in 1779. I believe I found this date in a book called The Story of the Dining Fork, which is a family history of the Harrisons settling in the USA (referring the the Dining Fork river in Ohio).
He and Rachel Harrison were married May 18, 1808.
I don't have a death date for James either.