When Strawhorn plans his breakout on the train, he rigs a garrote from a piece of wire taken apart from a broom and lashes Wesley tightly by the neck to the bars of the cell. Later when Wesley answers Strawhorn's call to come to his room where Nightingale is kept hostage, there isn't even the slightest hint of redness or abrasion on his neck from the event.
Howard Nightingale breaks his fall with hands that are supposedly cuffed behind his back.
(at around 21 mins) When an outlaw is being "crushed" by a burning wall in the opening raid, he may clearly be seen going backwards and headfirst into a hidey hole screen left.
US Senators were not directly elected at the time of the film's setting. They were appointed by State Legislatures until the 17th Amendment in 1913.
Supposedly set in Texas yet the train passes many saguaro cacti which do not grow in Texas.
Howard Nightingale tells Mrs Cooper that he doesn't want her sympathy, he wants her vote. At the time the film is set, women did not have the vote in the US.