Factual error: In the scene after the Mandingo fight in the Cleopatra club, when Leonardo DiCaprio gives his slave a beer, it is served in a flip top bottle. The first flip-top closure was created by Charles de Quillfeldt in the United States, who filed for a patent on 30 November 1874, receiving patent number 158406.
Factual error: Dr Schultz pays with 12 $1000 bills, but $1000 bills were not created until 1861, after the time period of this movie.
Factual error: In several scenes throughout the film, characters are shown wearing pants which have belt loops. While belts were used in the past, belt loops on pants did not come into usage until the 20th century.
Factual error: When they enter the big house after the funeral, Sam Jackson is singing "In the sweet by and by", the song was written in 1868, the film is set 10 years earlier.
Factual error: At the end of the movie, Django has a bundle of dynamite strapped to the front doorframe of Candie's house and uses it to blow up the place. The explosion caused by that bundle was way too large compared to the amount of dynamite used. It also shows the house exploding from the center out, distributing debris almost equally in all directions. But the dynamite was at the front door so most of it would have gone backwards.
Factual error: When Django blows up Candyland at the end with a bundle of perhaps 30 or 40 sticks or so of dynamite, he casually moseys out the door, and turns around and watches from maybe 100 feet away. With an explosion like that, completely obliterating an entire mansion, from that distance, the shock wave would have sent him flying and probably killed him. He was far too close to be safe and emerge unscathed from the explosion.
Factual error: There are no Live Oaks growing in Tennessee. They can be seen in several outdoors scenes.