I haven't done a lot of research into the Bozarths, as they are only related to me by marriage, but I can tell you that John R. Bozarth's parents were David Bozarth, b.c. 1790; d. between 1830-1840 in Gallatin County, IL. He was married c. 1819, presumably in KY, to Nancy Wilson, b. 13 Jun 1805 in KY; d. 1 May 1870 in Henry County, MO. I don't have any proof about his parents, but his father may have been Israel Bozarth/Bozorth, who appears in Illinois land records.
Since posting this, I have found out that John R. Bozarth's wife's surname was Williams, not Oskins. The confusion arose because her mother, Harriet, was married 3 times - her final marriage was Oskins. I found their marriage record not long ago; they were married 11 Aug 1865 in St. Clair County, IL. I have no information on how a girl from AR met and married a man from IL during the time of the Civil War - that could be a story in itself! As you probably know, they settled in Henry County. MO and are buried in the Bozarth Cemetery there, as is Harriet Oskins. Mary Bozarth's sister Martha Williams Adair is my g-g-grandmother, and Mary [aka "Aunt Molly"] raised my orphaned g-grandmother, Piaetta Adair Silver.
According to my information, John and Mary had 1 son, Joseph, and 4 daughters, Harriet [Hattie], Fanny, Ida, and Effie. Which of these is your line? I have a couple of old photos that may be of this Bozarth family. If you have any old photos of John and Mary or their children, I would love to see them, so I can verify the ones I have.