I am researching Purdum. Benjamin Purdum had heirs, in addition to his other children, John and James Abernatha/Abernath (they are named in Illinois court records with these two spellings). Benjamin Purdum was living in Ross County, Ohio in 1830. Immediately next door to him was Samuel Abernathy, probably the Samuel Abernather who married Casanda Purdum in Ross County 3 Sep 1828.
In 1850, Samuel Abernathy is living in Brown County, OH, Perry Twp., with sons John, 20, and James, 17, both born in Ohio, as well as a wife Mary A. and other children named Sarah, 15, and Isaac, 13.
Is it possible that the Samuel Abernathy living in Clermont Ohio in 1840 is the same man who was living in Brown Ohio in 1850? The ages of the children and the adult male match. Mary could be a second wife (although I have found a posting by Elizabeth Ferguson that indicates Casanda Purdum was 2nd wife to Samuel Abernathy).