I have just started checking message boards for the various names in my families trees. My husband's grandfather, William Mellroy Craven, put together a family tree type of booklet (dated May, 1929) which included the following comments about the Diefenbach/Deafenbaugh line(s). The comments are not documented.
"The name Diefenbach is, no doubt, more or less of French origin although it sounds decidedly German. Adam Diefenbach's father fought under Napoleon during the Napoleonic Wars. With the wars over he settled in Germany marrying a German woman. They had one son Adam and then the father died. The mother and son then came to America and settled in Pennsylvania. Adam married twice. By his first wife he had two sons and one daughter. The oldest son was named Adam but I have been unable to get the names of the others. By the second wife he had two daughters and one son. The son, named Jacob A. was born in Tuscarawas County, Ohio, July 4, 1846.
In 1875 Jacob A. Diefenbach move to Rock Island, Illinois. At this time he had the spelling of his name changed to Deafenbaugh which has since been the name of his family. From Illinois he moved to a farm in Garfield County, Nebraska in 1878. On the 24th of March 1879 he married Rosina Margaret Schreier of Milan, Illinois. To this union there were born five children, all at Burwell, Garfield County, Nebraska as follows: Cyrus Carl born Apr. 27, i880; Louisa Carolina Oct. 8, 1881; Mary Emma Oct. 1, 1884; Anna Amelia Jan. 27, 1886; Frederick William Jan. 21, 1888."
It would seem that your grandfather, Jacob, and the one mentioned in this "Craven Family History" are the same person, although there is some variation in the details. Have you acquired any more background information on the family line? If you have citations for your information I would appreciate being able to add them to my notes. Thank you Judy Craven