Whenever I see Thomas Mitchell, I can't help but think of Uncle Billy from It's A Wonderful Life.
Here are some other perspectives -
http://www.thegoldenyears.org/mitchell.html
http://www.movieactors.com/winsm/sm39.htm
http://www.nndb.com/people/116/000063924/
http://www.filmogs.com/profile.php?id=547
Mrs. C 
