Kimberly, thank you for your generous offer of sending the full biography of Hiram. I would love to have it. I'll let you know where I live when you email it and if there is anything here that I can research for you, just let me know.
David was born in February 1869, so I don't know why he doesn't appear in the census. Perhaps he was staying with relatives? Another family member discovered that Amanda Wilson Cox was my GGG grandmother.
From what I remember from Grandma talking about her Dad (David Cox), he was the black sheep of the family. It is also from her that I know David had brothers named George and Teddy.