Broadly, yes. Lincoln was the President during the American Civil War that eventually ended slavery, and many lines that he is given in the film, especially his famous public speeches, are taken from actual records. The film concentrates on quite a short period of Lincoln's life and accurately depicts the way he died, and gives a good feel for the political events of the time. It's also felt that Daniel Day Lewis has captured his personality and the effect he has on people.
Historian disagree on how accurately the film portrays the more exact political details - for example, how far the President was in agreement with his own party over key legislation. A more serious problem is that the film tends to imply that ending slavery was Lincoln's one aim and that he freed the African Americans more or less-single-handed - whereas in fact there was a very strong abolitionist movement, and there were numerous slave revolts and other acts of resistance that may have had more to do with ending slavery than the war itself.