17 Stupid Mistakes That Somehow Made It Into 2016 Movies

After plantation owner James Eakins (Joe Chrest) swears an oath, he returns to his home and, upon opening the door, a modern-day thermostat is clearly visible on the wall, out of focus but still easy to spot.

While some might try and argue that the thermostat did actually exist by the 1860s, it would've looked incredibly crude compared to the compact, clearly relatively new thermostat hanging on that wall.

It may not be a deal-breaker (though the film itself is quite tedious itself), but it's pretty hilarious all the same, especially given the historical context and clear effort put into making it feel as authentic as possible.