It seems that you and my wife are related through the McDOWELLS, and I'll respond to your post on John Henry McDOWELL on the McDowell Family Genealogy Forum.
The 1860 Census of Dayton Twp., La Salle Co., IL, lists David FURROW, age=60, a (wealthy!) farmer, b. in VA. His children, all b. in OH, were Daniel (30), John (25), Joseph (18), Mary (20), Ann (13), and Zacharias. David's wife, Sarah, d. 6 February, 1859, and was interred in the Brower Cemetery in Dayton Twp. She was 55 years old. John FURROW, b. circa 1835, was obviously the one who m. Elizabeth Ann McDOWELL in La Salle Co., IL, in 1867. John's sister, Margaret Ann FURROW, was the 2nd wife of Judge Hammond Healy BROWER. She was b. in May, 1834, and they were m. in la salle Co., IL, 30 March, 1858. Hammond & Margaret (FURROW) BROWER had four children. Hammond BROWER & his first wife, Mariette CROSBY, were my wife's 2-great grandparents.
Although Sarah FURROW'S maiden name is unknown, I did find a marriage record in Union Co., OH, that may be the correct one. David FURROW m. Sally WALFORD 29 November, 1822.