Hi Carol,
My grandfather was Charles Emory Biby, Jesse's brother.
I have been looking for Jonathan P. Biby's father McCager Biby for many years. I now have proof that Micajah and McCager are the same person. I also know that there is a Micajah Jr. who is listed in the 1860 Census. Micajah Sr. died about 1837. I have his Marriage Bond (Micajah Bibee & Mary Buckner, Macon Co. 6 Mar 1818) and his wife's application for Bounty Land (Micajah Biba & Mary Biba, 1 Feb 1858, Augusta Co.) from his service in the War of 1812.
I have been working on four Biby Family Trees at the same time. You can see why we all have had so much trouble finding any info of them also remember none of them could rear or write. That's why the name is spelled so many different ways.
I'm pretty sure that they will all come together with Micajah Biby Sr.
I hope this will help you in your search.

Ken