I checked the book History of Ogle Co,IL 1876 and there is a biography on Hiram S Cox who married Amanda, daughter of Edward Wilson, of Pine Creek Tp. It lists their 3 children and they do not mention a David. They list Florence b 1865, Theodore b 1867 and George b 1872. From another source, I was told that they had another son Bert b 1878. Maybe your David is not the son of Hiram and Amanda. If you want the full biography on Hiram let me know and I will send it to you. I could not find anything on your Travers.