Factual error: When the whore is talking to Lily, she says "The first thing she should do (in her new tent) is to get the carpenter to lay some boards, or she will be saying hello to Mr. Trench Foot", referring to the medical issue related to feet in wet and unsanitary conditions. This disease of the feet was not referred to as this until World War One. (00:23:10)
Revelations - S1-E7
Factual error: During the race between the horse and the train, the horses are wearing shoes. The Native Americans had no way of forging steel to make horse shoes.
Factual error: In the scenes where they show the flag it's a modern day 50 star flag.
Blood Moon - S2-E9
Factual error: The package that Lily gives Elam has a modern day computer printed postage label. (00:32:12)
Factual error: Immediately after Cullen Bohannon is blown out of the blasting hole and is helped up off the ground, a footprint is in the dirt/snow on the ground behind him is revealed that is made from a modern shoe. It's a complex impression made from a cast rubber sole of some sort. (00:15:10)
Factual error: In the shot where Bohannon and Swede are walking down the tracks, to the far left below the gatling gun there is a man presumably dead, wearing a modern orange hardhat. (00:39:40)
Factual error: The steam locomotives seen are dull faded gray. The railroads of the 1800's had great respect for the trains that brought their business. As such, their locomotives (even those in freight or yard duties) were painted in vibrant colors, with their bells, whistles, and other brass components highly polished. The replica engines at the Golden Spike National Historic Site, as well as various other preserved 1860's and 1870's vintage locomotives all give you a good idea of how steam engines appeared during the show's time. It wasn't until around the turn of the century that corporate greed had taken its toll on the trains' appearances.