In the sneak peek below, Minnie learns more about her father and his humble beginnings, and sees a photo of her grandmother for the first time.
The finale of "Who Do You Think You Are?" airs Wednesday, August 27 at 9 PM on TLC.
"Extra" has an exclusive sneak peek at the season finale of "Who Do You Think You Are?" The episode follows actress Minnie Driver as she unravels the deep family secrets that her late father kept hidden.