As most of you know, I come from a family of history teachers. However, I do not come from Daviess County or is it Daveiss County? Let me explain. 

Google Maps

THIS is Major Joseph Hamilton Daveiss, for whom all the Daviess counties in the US (Kentucky, Indiana, and Missouri) are named. A little about him, he was born in Virginia and his family eventually settled in Danville, Kentucky. He served as US District Attorney for Kentucky. Daveiss went to serve under then Indiana Governor and eventual President William Henry Harrison in the Battle of Tippecanoe and he would eventually be morally wounded. Major Daveiss died in November, 1811.

Daviess County was established in 1815. So why the misspelling? A state clerk made an error when entering the Major's name and the error became permanent and all places named after Daveiss are spelled as "Daviess". What is the rule? I before E except after C?