I realize this message is antique by now!Hope this reaches you!
I have an Isaac DAVIS, my gg-gfather.From the records I have, there is a typed note from his son, Finley Clark DAVIS, indicating that Isaac's parent may possibly be Stephen Davis, but his mother is not known.Isaac is said to be born in Warrenton, OH, Jan/Feb 1836.
I assume from the date of Stephen and Mary's marriage, it could be possible that this is Isaac's parents due to the year and location he was born.Additionally, I did a search on the 1880 US Census for a Stephan DAVIS to assist me on myresearch.Of the five I've narrowed, one does indicate a Stephen S DAVIS b. 1815 PA m. Mary S b. 1813 PA, living in Willistown, Chester Co., PA.
Was your Mary PATTERSON born on 1813 in PA?Do you have a list of their dependants?It could be possible that your Mary moved to PA later on after Issac's birth. (It was originallythought that Issac was born in PA, which may explain that he did reside there with his parents after his birth in OH - a relative doing the research confirmed the birthplace to be Warrenton, OH.)