It helps to have a sense of the history as to what the 13th Amendment is about. The movie is centered on the drama of how the amendment was passed. The moviegoer gets a sense of how government worked early on and still applies to how it works today.
Daniel Day Lewis was made for this role. He is amazing in his portrayal of Lincoln. He should receive a nod from the Academy in the Best Actor category. All the other actors were simply tremendous. Tommy Lee Jones is perfect in his role.
Understand that this movie is a lesson in history. There are no "car chases." The movie is all dialogue, but well paced. This is a movie, story, well worth seeing.