Shortly before leaving Mary Todd waiting at the altar (circa 1850), Lincoln opens a drawer and looks at a daguerreotype of his lost love, Ann Rutledge, who had died several years before in 1835. Dagguereotypes did not reach the United States until the mid-1840s.
When Lincoln is filling out his ticket for his luggage on the train trip to Washington, the familiar signature of ALincoln, which is familiar to audiences, is in an entirely different writing style that the destination of Washington.
In Ford's theater, Booth entered through a door behind Mary Todd, to the president's right. In reality, he entered through a door to the back left of Lincoln, and fired just below Lincoln's left ear. The movie also shows him jumping from the box through the far left opening (facing the front); once again, he actually jumped through the right opening, directly in front of the president, nicking the corner of Washington's picture with the spur on his ankle, causing him to stumble when he fell, breaking his ankle.