Eric Foner’s ‘The Fiery Trial’ is a good account of Lincoln and slavery. Foner is a nephew of Phillip Foner, historian of the American labor movement. His father Jack D. Foner, also a historian, was blacklisted because he was a radical. And Uncle Moe ran a union.
Foner has criticized some inaccuracies in the movie:
“Never before had so large a number of slaves been declared free,” Foner concludes. “By making the army an agent of emancipation and wedding the goals of Union and abolition, it ensured that Northern victory would produce a social transformation in the South and a redefinition of the place of blacks in American life.” All that is missing from Spielberg’s film.
http://www.thenation.com/blog/171461/trouble-steven-spielbergs-lincoln#
Another good book on the abolition of slavery is James Oakes just published “Freedom National’, which has a somewhat different take than Foner’s.