Trying to get a handle on my great grandfather, J. Robert L. Dunlap, probably born on 28 Aug 1848 and probably born at Coatesville, PA. His father's first name was John and he was born in PA abt 1816.

That is all I got on my great grandfather prior to his arrival in Constantine, MI about 1870. I have tried everything I can think of, including buying and reading Hanna's The House of Dunlap, with no luck.

Anyone have anything that can give me a lead or point me in the right direction?