My Burkes are hiding

Every genealogist has a brick wall or two (probably more) and mine is John Burke, possibly Junior according to notes written by my Grandmother. In her notes he is listed as being born on Nov. 29, 1835 and died on Jan. 2, 1872. Indeed I found his death listed in the Hancock County, Ohio death records for this date and I found out that he was born in Crawford, Ohio.
The first puzzle is what Crawford? Is it Crawford County or Crawford in Wyandot County? Of course there is a  John Burke listed in both. Just my luck. My John is married to Ellen Hill 1836-1871, and they both died a year apart. They can be found with their children in the 1870 census in Bath, Greene County, Ohio but they died in Ellen's home county of Hancock, Ohio.
Their youngest son, Elroy, died at age one and the two older boys, Calvin and William, were put under the guardianship of Ellen's brother Edward Chapman Hill. However, he did not keep them long as my second Great Grandfather, Calvin, is listed in the 1880 census as living in a boarding house and his brother William is no where to be found. In my grandmothers notes William is said to have died at age 18 but I cannot find a record of this event.
Getting back to John, I am wondering who is parents are and where they were born. I really want to track someone back to Ireland. So the search continues.