It is better to look at this movie as am amalgamation of the experiences of black families in the America of the last century. And it is a moving amalgamation.
Usually when a film comes out that deals with civil rights issues (or, even worse, slavery) you can count on box office failure. In this case? After one week in theaters this film is the number one film in the country. Guesses as to why this is the case are that it is the end of the summer and there is a dearth of new movies worth seeing and, Oprah Winfrey is in it.
Winfrey's last film, the underrated Beloved, underperformed (it was marketed as a "slavery" story when it probably should have been marketed as a "ghost" story). This film is marketed as just what it is. Some of it is hard to watch. Who want's to hear people called "niggers" and demeaned?
Ultimately, this film is about a generational divide. The father made his living as a butler, the son sees this 'servile' position as demeaning. They disagree on race relations and how change can be made. The son, ably played by David Oyelowo, is less a character than a representation of the change in attitude. He turns the other cheek and follows nonviolence but then changes. How is it that you stick to nonviolence when it seems to get you nowhere? Oyelowo brings this character, who could have been just a symbol, to life. He makes him human.
The film is full of cameos. Various well-known actors portray, in bit parts, some of which are only one scene, famous Americans--from Presidents to First Ladies to civil rights leaders to regular folks. Most of these work and those that do not are not particularly glaring. Many will find Winfrey's presence distracting. She is OPRAH. We all know her and it is hard to get past that. Yet she delivers a solid performance (she really should act more). There is some padding of her character that is, perhaps, a little irrelevant to the plot of the film but it isn't overdone and never brings the film to a grinding halt.
This is an entertaining film. It may not be an easy film to watch in all parts but has a humanity to it. It is, in parts, funny even. The characters are alive and real. You care about what happens to them. Some of the most heart wrenching events, events that seem "Hollywood-created" are actually from the life of Allen.
We know the basic story here, or it is to be hoped we do. But with recent events that divide the USA along racial lines? It is always a good thing to be reminded of the bad old days, days when things WERE worse. This doesn't mean things are perfect and racism is gone now. It shows us that, even when attitudes among the majority ranged from poisonous to indifferent, change was possible. How much easier SHOULD it be to move forward now? That is hopefully part of what people will take away from this film.