Just for clarification, the Jesse Yon referenced in my original post was the father of Dr. Jesse Yon Jr., who was the father of Braxton L. Yon. I don’t have too much on Jesse Yon Jr. or any of his descendants.
What I do have is that Jesse Yon Jr. married Sarah E. Lott, daughter of Luke Lott and Ann M. Thomas, sometime before the 1860 census. Jesse and Sarah had two sons that I know of: William J. Yon (born about 1859) and Braxton L. Yon (born 03/26/1864 and died 08/7/1956). Does this information match what you have?
I think Jesse Yon Jr. died sometime in 1865. He is listed on the 1864 Fall Term Juror List for the Calhoun County Circuit Court at Abe Springs Bluff. In the 1866 Fall Term of the Calhoun County Circuit Court there was a statement signed by Sarah E Yon where she was listed as Administratrix for Jesse Yon (Jr.), deceased, regarding a case between a Robert Johnson and James B. Stone. (James B. Stone was married to Jesse Yon Jr’s sister, Jincy Yon).
Like you I can offer no cause as to Dr. Jesse Yon Jr’s death, only speculation. Several members of Jesse Yon Sr.’s extended family died during the War, including my great great great Grandfather, Terrell Higdon Yon (b. 1820 Laurens County, Georgia and died in late 1863 or early1864).
I hope this helps.