Steven Spielberg spent 12 years researching the film. He recreated Abraham Lincoln's Executive Mansion office precisely, with the same wallpaper and books Lincoln used. The ticking of Lincoln's watch in the film is the sound of Lincoln's actual pocket watch. Lincoln's watch is housed in the Kentucky Historical Society in Frankfort, Kentucky (not the Lincoln Presidential Library). It is the watch he carried the day of his assassination.
Lobbyist William N. Bilbo's (James Spader) appearance was created from scratch because not a single photo of him exists. His eccentric presence was taken from various sources.
After Liam Neeson dropped out, Steven Spielberg returned to his original choice for the titular role of Abraham Lincoln: Sir Daniel Day-Lewis. Day-Lewis declined because he didn't know if he could play such an iconic role. It was Leonardo DiCaprio who convinced him to take the role after Spielberg told him that Day-Lewis declined. It is unknown how DiCaprio convinced Day-Lewis to take the role.
Sally Field (who got an Academy award nomination for her role in this movie) was so determined to play Mary Todd Lincoln, she begged Steven Spielberg for the chance to screen test alongside Sir Daniel Day-Lewis. Spielberg believed she was too old to play the part, but Field was adamant. She recalled, "I'm 10 years older than Daniel and 20 years older than Abraham Lincoln's wife was and Steven told me he didn't see me in the role. But I knew I was right for this part and begged him to let me audition for it. He was kind enough to do that and Daniel is such a sweetheart that he flew over from his home in Ireland to screen test with me. I'll love him forever for that."
Describing his experience playing Abraham Lincoln, Sir Daniel Day-Lewis said, "I never, ever felt that depth of love for another human being that I never met. And that's, I think, probably the effect that Lincoln has on most people that take the time to discover him... I wish he had stayed (with me) forever."
Steven Spielberg: [Lincoln] Abraham Lincoln themes have appeared in many Spielberg films. The "Bixby Letter" was an indirect plot device in Salvate il soldato Ryan (1998). The "Gettysburg Address" is recited by a schoolboy in the opening scene of Minority Report (2002).