Today's obvious statement: Quentin Tarantino is a hyperstylized director before he is a historically accurate director. Hitler wasn't killed by two machine-gun-wielding American Jews and a French Jewish cinema owner, but it was mighty cool to pretend he was. Django Unchained similarly takes a few poetic liberties with our past in the service of a particularly exciting piece of cinema. We looked at some of film's small details and tried to determine if they were temporally accurate to 1858 America.
Though things with similar functions as sunglasses have existed in some capacity since the fourteenth century, it wasn't until the early twentieth century that sunglasses as we know them today were widely worn. Maybe that's why everyone was always shocked when Django rode into town.
The word has been around in a variety of forms for hundreds of years. Its modern use dates back to its inclusion as a vulgar word in 1775's A New and Complete Dictionary. We can't imagine Tarantino would ever do a movie where his characters couldn't drop the F-bomb regularly.
John Lofting invented the original beer engine in the late seventeenth century. However, it was after Joseph Bramah developed and patented the technology that beer commonly started being served from a tap as opposed to a cask. An experienced German beer drinker like Dr. King Schultz would've been plenty used to beer taps by then.
The idea of a cake eaten to celebrate one's birth is a very old practice, but the "birthday cake" didn't become a common practice until the nineteenth century. Even then it was really only a practice of the middle and upper class. It's hard to say if a lonely sheriff out in the middle of nowhere would have the money or materials to have one.
Non-coil springs have been around for millennia, but the coiled spring began to appear in the early fifteenth century. So the giant bouncy tooth on the roof of Schultz's carriage would not have surprised the Speck Brothers.
Mandingo fighting, as it's portrayed in the film — where two slaves fight to the death — never existed. Slaves were just too valuable at the time for it to have been a real practice. Apparently, a real-life Calvin Candie would've had no way to kill all his free time, save flirting with his widowed sister.