According to an earlier researcher of the Mahon family, it is known that John Johnson Mahon came to Fayette County, Illinois in the early 1800's.  He must have owned slaves at that time.  In 1851 Johnson moved on to Osage County, Missouri where he purchased 640 acres of land.  It is believed that the cholera epidemic that claimed the life of his daughter, Rebecca, and perhaps the desire to retain his slaves, were factors in this move.  Johnson's sister, Susan, had married Robert Goodman, who ran a mill in what is now Rich Fountain, Missouri.  Also, Johnson's brother, William Pope Mahon, had already moved to Osage County.  During the War Johnson's livestock were taken from him twice by the soldiers.  Thomas, his son, died in 1857 and his first wife, Leah, died in Missouri in 1863.  The 2 are buried in that county. Johnson then left Missouri to return to Fayette County, Illinois where it is believed that he spent the rest of his life.  He is buried in Lone Grove Township.
     Below can be seen a page of the 1860 Osage County, Illinois Slave Schedule.  Johnson Mahon is listed as the owner of 3 slaves at that time.