I recently came across your message on the surname bulletin board. I, too, am descended from John and Sara. If you are not aware, one Warren McCroskey of Ft. Wayne, Indiana, published a partial family history of the McCroskeys in 1992. That book, if still available, contains much information on the McCroskey lines decending from John and Elizabeth McCroskey, the parents of the John who married Sara. I have a copy of the book as do my parents and brother. If there is anything from that resource that would be of interest to you, I would be pleased to provide it.