John:
I do have information on a John F.Casper born in Union Co.,Ill., on 3-20-1838. His father was Caleb Casper from North Carolina.Caleb was born 1812 and married to a Esther Fullenwider.
Look at the messages on Fullenwider, there you will finmd more information.
If this answers your question please feel free to send me your address and I will send you the article.