My 4xs great grandmother was Jane J Leeper. I have the date that Jane married James in Franklin county IN, which the next year became a part of Union county. Yes, they did move to Mercer County IL and I have Jane and James there until their deaths.
I also found some legal documents after William Leeper died. The 3 boys, Jamison, Samuel and William have to have their mother declared their guardian.
The names Bonner, Stewart, etc. are listed in the legal documents.