Query: KELLY/KELLEY of Sullivan County

I am researching my second Great Grandfather's parents. Joseph A KELLY or KELLY was born in Merom, Sullivan, IN, 12 June 1837 and d. 04 December 1912 in East Newburn, Jersey, IL. His mother may have been Polly or Mary, based on the 1850 US Census record. The family came from Ireland and were Cumberland Presbyterians. I inquired about records from the church but have not gotten any responses. I want to know who Joseph KELLY's parents were. I have visited the Courthouse in Sullivan Co but their records burned in 1850. Thank you, Verna Piper 1020 West Boone Street Salem, IL 62881-1127 vpiper2370@ussonet.net