Factual error: When Mrs. Lincoln is greeting the guests at the party, she says, "The White House and the other house." The presidential mansion was not called the White House until Teddy Roosevelt gave it that name in 1901.
Suggested correction: Teddy Roosevelt only made the nickname "The White House" the official name in 1901. The nickname was used in the 1800s.
Revealing mistake: When Stevens leaves the house about halfway through and sits on a bench there is a modern electrical outlet on the wall to his left.
Continuity mistake: In the scene where Tommy Lee Jones takes home a copy of the bill it is folded lengthwise, when he hands it to Epatha Merkeson it is folded crosswise.
Factual error: In one of the scenes in which took place in a white room, on the door behind the character's head is a modern day "door closer". Door closers were invented in 1880 by Lewis C Norton of the the LCN Company and the first one was installed at Boston Trinity Church in 1880, was some 15 years after this film took place.
Factual error: In the flag ceremony Lincoln raise a US Flag with 35 stars which was in use from 1863-1865. Later, Lincoln is riding through the aftermath of a battle scene and the soldier following is carrying a flag which matches the 1877 US flag with 38 stars.
Continuity mistake: When Thaddeus Stevens tells Lincoln that the people elected him to represent them and he should try it, Lincoln's head is directly facing Thaddeus. In the next shot his head is down and certainly not looking at Thaddeus.
Visible crew/equipment: In the scene where Lincoln and his son arrive at the Army Hospital in the horse-drawn carriage, look at the dirt road in the background. If you look closely, there appears to be tire tracks from tires of a modern-day vehicle.
Continuity mistake: When Thaddeus Stevens is seen for the first time in the movie (in his office), there is a bust near the edge of his desk. But when Thaddeus stands up, the bust is at least 5 or 6 inches further away from the edge.
Revealing mistake: In the first scene with Lincoln and his cabinet in his office, in one close-up of Lincoln you can see that Daniel Day-Lewis has a pierced left ear, which Lincoln definitely did not.
Continuity mistake: When Lincoln is giving his soliloquy about abolishing slavery, if you look close, Secretary Seward"s elbows are on the table with his hands folded and his chin resting on them. Soon after, When Lincoln says "Blood's been spilt to afford us this moment!" you'll see that Secretary Seward pulls his elbows off the table and onto his lap. The next cut is Lincoln pointing to Seward and the rest of the bunch screaming "Now! Now! Now!" At this time, Seward's hands are back on the table in the exact position they were before. (01:45:00)