Continuity: When Will, who is black, is in the carriage, he is the only person on it. When you see a close up of the horses, you can see a white persons foot dangling from the carriage.

Continuity: When Artimus is showing Rita the billiard balls on the Wanderer, they are all stipes, but when Arti puts his hand back down on the pool table a few frames later, a red solid is in his hand.

Factual error: In one scene Jim West is walking up to the White House. There is a cast-iron gate surrounding the White House, as there is today, but he gate was not added until the 1930's.

Factual error: West and Gordon are outfitted with massively powerful magnetic collars. Somehow the two collars don't interact with each other at all until they try to remove them, when they prove able to attract each other from at least 20 meters. Gordon rationalizes this by saying that they accidentally reversed one magnet's polarity, but if this were so then the magnets should have originally opposed each other with the same force, instantly throwing each other apart as soon as they were brought within meters of each other. Nonsensical.

Factual error: The Secret Service was created under Abraham Lincoln's presidency in 1860, not under Ulysses S. Grant's.

Continuity: In the shot where McGrath punches West in the face, he has the hearing thing in his ear. Next shot, when he runs away, he doesn't have the hearing thing in his ear.

Factual error: In the scene where Grant is trying to drive the railroad spike in at Promontory Point, current 50-state US flags are visible on the train.

Continuity: During the brothel scene, Loveless is seen near the cart containing nitro-glycerine. We see him pull the hinge out of the cart and the cart rolls down the hill and into the brothel. Now there's two things wrong with this scene. First, it wasn't a small hill, it was a small cliff that was near the brothel. And second, where did the horses pulling the cart go?

Continuity: In the scene where Jim West is walking up to the White House we can see different shadows: the ones generated by the bodies of people in the street go one way, but we can clearly see that the white house dome has light coming from the same direction as the people's shadows are going. The White House's shadow goes in the right direction for the light.

Continuity: As the tank pulls out of the lagoon, it has no seaweed on it until it is fully out of the water.

Continuity: After the cornfield scene and the heroes fall into the mud river, their clothes and metal collars are seen to be covered in mud. In the next scene featuring them, their clothes are muddy but their metal ring collars are totally unmarked.

Factual error: At the beginning of the movie, we see that the scientist who was killed was wearing his glasses. Hence, his last image would have been a clear one. Of course, the whole process of projecting a man's last sight by means of a light shone through his retinas is preposterous.

Factual error: The nitroglycerine would have exploded when McGrath's men threw it roughly onto the cart, leaving no risk of it exploding later when West makes his comment that this is not the way you transport nitro.

Factual error: As Jim and Artemus leave the White House heading for the Wanderer, they both head south. However, if they're taking a train from Washington to the west in 1869, they've got to use the B&O's track. The B&O station was north of the White House.