I am delighted to hear from you, Cathy. Your father was right that all Hadaths are related - I have traced all known Hadaths and Haddaths back to a common ancestor named William, who married a lady named Agnes Boulton in Cumbria, north-western England, in 1767. The results of all the family history research is contained in a book which now runs to more than 200 pages. I will send a message directly to your own e-mail to follow up on this.
Best regards
Dick Chandler