...brings it home, where he is greeted by his Black housekeeper Lydia Smith, played by S. Epatha Merkerson. He presents it to her with the words “a gift for you,” whereupon the satisfied servant crawls into bed with the White man, for a night of emancipation fornication, one assumes.
I'm not familiar with the actual facts of the Stevens-Smith relationship, but my interpretation of that scene in the movie was that Stevens and Smith were in a long-term, comfortable, romantic relationship and Stevens felt, accurately, that Smith would appreciate seeing the real, genuine words of what represented freedom for her people. Yes, emancipation resulted in a very real improvement for black people for a number of years, then white America kicked back, ending Reconstruction, and what followed that was nearly a century of conditions that powerfully resembled slavery. Greatly improved conditions followed that were brought about by the Civil Rights Movement and by white people who wanted to see America fulfil its promise as a land that treated all people with dignity and respect.
I don't see the movie as glossing over Lincoln so much as it introduces a game-playing Lincoln who made necessary compromises when ha had to and who juggled many balls at once, trying not to let any of them drop. There were points where both Lincoln and Stevens said things they obviously didn't believe to be true (Though Lincoln used a semantic dodge to prevent his statement from being an outright lie), but both of them agreed that freedom for the black people was a good thing, even if their methods of achieving that freedom had to be a bit indirect and had to involve covert appeals.
Are the black people seen as one-dimensionally grateful to the white politicians here? They certainly play a secondary role here. They certainly are not the primary characters around whom the plots of the film revolve. So, up to a point, yes, blacks are seen in the light of being the grateful recipients of what Northern whites do for them, but I reject the idea that blacks played no role in their own liberation. I think that the entrance of blacks into the House gallery before the critical vote probably strengthened the resolve of the Congresspeople who decided to go against their peers and most likely, against a lot of their constituents back home by voting for the 13th Amendment. So I see FinalCall's interpretation as an overly simplified one. Could blacks have simply freed themselves by their own efforts? The South had taken many measures and a great deal of thought and time and effort over the preceding centuries to prevent rebellion by their slaves. No, I think the blacks of that era simply didn't have any choice. If they wanted freedom from chattel slavery, they had to work with Northern whites, which they did, to the ultimate benefit of both groups.