I am at a dead end.  My Great-great Grandfather, "Jack" Maxwell (John??), appears in legal/public documents in Lawrence County, in Southwest Missouri, in about 1848, where a courthouse entry shows he married Sarah Berry (or Beerry).  Later census documents reveal that Jack was said to have been born in Tennessee.  Although this is somewhat vague, if anyone has information which seems to intersect with this, I'd love to hear from you. Thanks.