I did a very quick search for your William Shook and it appears he died serving during the Civil War. Census records indicate both he and Margaret were born in TN. This William has a very high probability of being descended from Johannes George Schuck (www.shookhistory.org. If you have a male family member that is a Shook I would suggest doing DNA.I will look through McMinn County TN records and if they are abstracted maybe I can find you a clue.
Shook family reunion is first weekend of May 2014 in Clyde NC. lots of genealogy will be happening.