Continuity mistake: When Quinlan is with Joe Grandi at the bar, Quinlan breaks his sobriety while seated at a round table, but in the last overhead shot the table is rectangular. (00:57:00 - 00:58:25)
Continuity mistake: In the scene towards the beginning where pair- chained interracial prison escapees Noah Cullen and Joe Jackson (Sidney Poitier and Tony Curtis) are trying to cross a river together without killing each other, they get carried away downstream and are stopped by a tree. The mistake is, Sidney Poitier's bald headed stunt double is noticeable losing control while floating downstream, visibly and audibly crashing head first into the tree. He is briefly flailing and struggling from the unexpected impact until Sidney Poitier reappears properly floating towards the tree without struggle. This mistake is less than 30 seconds and is awesomely noticeable best on Blu-Ray disc. The shot of Tony pulling Sidney out of the river concludes the scene.
Factual error: The film begins in 1860, but the majority takes place 20 years later, so 1880. When James Rankin obtains files on the Haymarket Strangler/Edward Styles case we are shown another box labelled with details about Jack the Ripper, who wasn't active until 1888.