Continuity mistake: When Annabelle is helping Johnny fill the locomotive water tank, the water spout comes loose and Annabelle gets soaked. A few seconds later, her hair and clothes are completely dry again. (Later, in her memoirs, Marion Mack said she was not told this would happen and it was a complete surprise to her!). (00:51:00)
Factual error: The General in the film has marked differences from the real engine as it appeared during the Civil War. The engine had three domes rather than two, and had ankle bars extending the full length of each side. The General in the film more closely resembles the prototype's post-1893 appearance.
Factual error: Keaton's "General" locomotive is numbered '3' in the film, and the "Texas" is numbered '5'. The Western and Atlantic Railroad, like other railroads throughout the southeastern US, had only given its engines names, not numbers. The railroad began numbering its engines after the war, giving the General and the Texas the numbers '39' and '49', respectively. The General was renumbered 3 in 1880, at the time being the third oldest engine on the roster. The Texas was renumbered 12 at this time, then 212 in 1890, never carrying the number 5.