I found the last name of William Oglesby's wife, Sarah "Sallie" B. If the information is correct, her maiden name was McKinley. The information was found because one of William and Sarah's daughters, Minnie Camella Oglesby, had someone in her family who posted her information online. God bless the internet.
I emailed the information to Vic Oglesby, who trusted my information enough to add it to his database, and emailed the contact for the information posted on Minnie. To say I'm excited by this breakthrough is an understatement.
It still feels like these ancestors and "cousins" want me to find them. I hadn't been able to find any information on William J. Oglesby, or on ANY of the siblings of Morgan, for a very long time and suddenly I am finding so much that it's frightening. Now if I could only find out for sure which Oglesby family Daniel belongs to, I'd be a happy woman.