I am also a descendent of Henry Oliver File.Most of what I know about them was from Bond Co.,IL.I was told there is a book of File family history at the geneological society in Greenville. After looking further, I saw you were also researching the name Plant.That line is also in my family. I have an Elizabeth as one of 11 children between Williamson Plant and Elizabeth Watts. There appears to be several Elizabeths.My records show them coming from VA. If you would like to compare notes you can contact me.