Iam going to share what I have found with you. In 1850 Jones county federal census there are several Amos Koonces. I have mainly focused on Amos Koonce of the Tuckahoe district of Jones county and Amos Jarman Koonce of the Beaver creek district.
Amos Koonce of the Tuckahoe area is the father of the children that you have listed here. Leah is my gg grandmother.
She married Lewis D Humphrey of the same area. Ihave only the census records of Amos,Leah,and John Isaac. Ther are records in the abstracts of Jones County indicating that he was an heir of Elijah Koonce. I never found any legal record indicating that his initial was J or name Jarman
Amos Jarman Koonce was probably a cousin. He was born 1809/1812. He was the one that married Elizabeth Reyonlds.
They are buried in the Trenton cemetery located in Trenton,Jones county, N.C. He also married Ann Devaul.He has a will with Ann as Executor No children are mention in this will. He died about 1856? I do not know who his parents were. Usually the maiden name of the mother are given to male children to carry on her name. Elijah wife's name was Temperance Blackshear. Elihah had a son named Elijah Blackshear Koonce. This is an example of what I am referring to.
Amos Koonce is still living in 1860. He is still in the Tuckahoe area. He died between1860/1870. Maybe if we allwork together one of these days we willfind the information we are looking for.
Have you tried to see if there is any information on the marriage bond of John Isaac. Some times Father and mother maiden is given. If we knew who the other childre married that would be something we could pursue.
Sorry I cant help you that much. Please stay in touch. My gg grand mother died very young so we never knew much about our Koonce Family. I was a missioary for the LDS church and served in the Family History Library in SLC,Utah. This is where I became acquaint with our Koonce ancesters.
Your Cousin Mary Eva