I think you may have 2 John Conns confused; an elder John Conn whose will was probated in 1801 in Franklin Co, GA (who married Elizabeth; you show Boling) and had most of those children you listed and a younger John Conn (who I believe was a Dr.) who married Anna Smith in 1820. (*He would already be dead in 1800, so could not marry in 1820).

This John and Anna (Smith) Conn was found in Marshall Co, AL ca 1860 where their son in law Elisha Gentry (who m1 Elizabeth Conn) and daughter (Elisha's m2), Sarah Ann, are living with them. Elisha and family later went to Stephens Co, TX where they presumably are buried.

The Conn line is very confusing. I descend from Joseph Conn b/1805 who m/Hannah (LNU) and who had Simon S. b/1826 who married Alsrey Gentry (presumed sister to the aforementioned Elisha Gentry). They went to the Etowah / St. Clair Co, AL / Marshall Co, AL area also.

I've been having a time trying to find the father & siblings of Joseph Conn or his wife Hannah, as well as their daughter-in-law Alsrey Gentry.

Working on a theory that the elder John Conn (will 1801 Franklin Co, GA who had children: Agnes, Caty, Isaac, Jane, John, Mary, Peggy, Samuel, Simon, and Thomas had as 2 of his sons the John b/1794 m/Anna Smith, Samuel b/1809 m/Elizabeth Ingram, and possibly my Joseph b/1805. The locations and dates match up, though I cannot fathom why Joseph would not be mentioned in the will (unless he was listed by his middle name?). There is also a theory that there were 4 Conn brothers who came from NC to SC to GA: John, Joseph, Samuel, and Thomas, which would also match.

John b/1794 m/Anna Smith had a son Simeon A b/1824 (often confused with my Simon b/1826) and Sarah Ann who m/Elisha Gentry. (Presume Elisha's first wife was also their daughter, but cannot prove it as yet. I need to look again at the 1850 Cherokee Co, GA census to see what it indicates).

My Joseph b/1805 m/Hannah had son Simon b/1826 (close to the name of Simeon above & about the same date) and he married Alsrey Gentry. (i.e. close connection to the presumably same Gentry family).

Samuel b/1809 m/Elizabeth Ingram had a daughter named Alsie (or Alsrey?) Elizabeth Conn who m/Bedney Franklin Holcomb.
Similarity of name in Alsie/Alsrey.

In 1830 Hall Co, GA there is a John Conn and a Joseph Conn. I have been wondering if this was Dr. John m/Anna Smith above (& records indicate it was as they were married there) and my Joseph Conn. Oddly enough, I don't run across a lot of Joseph Conns, especially of his approximate age.

I would feel more confident if I knew what Joseph's middle name was or why he might have not been listed in the elder John's will (assuming that was his father). But for a long time researchers have suspected my Joseph was related to this specific line (brothers, cousins, etc), but not the exact link. So far this theory seems to fit the best in my mind.