We don't have any recordings of Abraham Lincoln's voice, but we do have some first hand recollections of it. While Lincoln tends to be depicted in film as a deep-voiced, grand orater, evidence shows that he was actually higher pitched and maybe a little nasally. Less rumble, more whine.
This is surely something Daniel Day Lewis has taken into account in his portrayal of Lincoln in Spielberg's Lincoln. But is that his voice over the teaser above? It sounds nothing like DDL, and with the slight Southern drawl I'm not even sure it's supposed to be Lincoln anyway. If that were to be DDL, this would be an almost unprecedented vocal transformation.
The teaser doesn't give us much of a sense of anything, really. Although the shot of Lincoln standing above a black soldier is interesting; Lincoln's views on slavery and equality were complex, and when the war began he thought it best to send all the freed slaves to Haiti after the fighting ending. And Frederick Douglass tried to get Lincoln to offer black soldiers equal pay and opportunities for advancement; it wasn't until 1864 that black and white soldiers were given equal pay.
Thanks to Josh Dickey of Variety for even making me pay attention to the voice in the first place!