Very compelling (the political horse-trading scenes especially; I think the decision to focus it so squarely on the thirteenth amendment instead of turning it into some dumb Lincoln biopic was a very good one) until Spielberg had to go and ruin everything with his goddamn stupid ending.
Oh yeah, the movie should have ended with the celebrations of the Amendment's passage. There really was no need to continue up to the assassination we all know about anyway.
I didn't see the ending, but I figured that is how it would have ended. IMO, the movie would have ended with the celebration of the amendment being passed and then skipped ahead to a very brief final scene on the assassination that would have highlighted how Lincoln literally was a martyr for freedom.