It is possible that this might be another William Blackmore. It is an unusual name though. This William O. Blackmore was one of the murderers of the infamous "Bushwacker" Bill Wilson of Phelps County in January 1869. Blackmore and John Thompson. both of Missouri, ambushed and killed Bill Wilson south of McKinney, Texas. The local newspapers printed their last letters to home. Blackmore had always been referred to in the papers as William O. Blackmore, the McKinney Enquirer, in particular. Blackmore's letter to his mother was sent to Carrollton, Carroll County, Missouri. In Blackmore's last words in the gallows, he states he joined the Confederate army at age 15 and was in the company of "very wicked men; they were my companions", copying their behavior, and eventually led to this murder. Blackmore may simply be buried in Texas after he was hung but I was hoping someone might know of his body's return to his home or may have more info about the family.
I have the books you mentioned and read about the references of Anderson's Blackmore. Thanks for the help.