Thanks very much for the Clondrohid information. I found a website listing the census and tithe info for the civil parish of Clondrohid here: http://corkgen.org/publicgenealogy/cork/potpourri/corkancest...
There are several Creedens listed with various spellings.
I think I have found enough information in the US Ohio records to confirm that my Timothy is Julia's brother. I'm still sifting through all the information, so I'll continue posting on my blog as I go through it. I'll also do some more searching on www.rootsireland.ie
and post if I come up with anything new. Thanks again for your help!