Stephen G. and Barbara R. (Griffith) Bishop also lived in Kimble County, TX in 1880. Mottie (17) and William Tucker (14) are listed as step-children in this household, both were born in Arkansas.

I still not certain who your Tucker was, he may have served in a Arkansas unit with his brothers-in-law, one of whom was Colonel John Griffith, older brother of Barbara R.

Some family data for Col. Griffith is provided at this link.
http://www.geocities.com/Pentagon/1117/j_grfth.html