I found the marriage record of Thomas and Sarah Erwin as follows:
KENNEDY THOMAS E. ERWIN SARAH JANE Lawrence 01-28-1849
There is a David Kennedy in the 1840 Clark Co., IN census that has a son the age that could be Thomas.There is also a Matilda Kenedy in the 1840 Lawrence Co., IN census that has a son the age that could be Thomas.
Can’t find them in the 1850 census???
1860 Wood Twp., Clark Co., IN census: Thomas E. Kenady32farm laborerb. IN Sarah J.26b. IN Frank M.11b. IN M.A.8b. IN Thomas C.3b. IN William?/12(cant read months)b. IN
1870 Cass Twp., Greene Co., IN census: Thomas Kennedy42farmerb. IN Sarah J.38KHb. IN Frances21farm handb. IN Matilda A.17b. IN Thomas C.14b. IN William F.9b. IN Louisa J.7b. IN James S.5b. IN Nameless7/12b. IN Nameless7/12b. IN
1880 Turman twp., Sullivan co., IN Thos. E. KENNEDY Self M Male W 52 IN Farmer KY VA Sarah J. KENNEDY Wife M Female W 47 IN Keeping House IN MD Matilda A. KENNEDY Dau S Female W 27 IN At Home IN IN Thomas C. KENNEDY Son S Male W 23 IN Farmer IN IN William KENNEDY Son S Male W 20 IN Farmer IN IN Loueda KENNEDY Dau S Female W 17 IN At Home IN IN Sherman KENNEDY Son S Male W 14 IN At Home IN IN Raphael KENNEDY Son S Male W 10 IN IN IN Dicy KENNEDY Dau S Female W 10 IN IN IN Mark KENNEDY Son S Male W 7 IN IN IN
Hope this helps.You may want to try to get a death record on him and see if his parents’ names are listed.That has helped me a few times.