Factual error: William Fuller in the film is seen chasing the General first on a push car, then on the Yonah, and finally on the Texas. In the actual chase, after leaving the Yonah, Fuller pursued on the Rome Railroad's William R. Smith locomotive, which is not featured in the film, before finding the Texas.
Factual error: The Yonah in the film, portrayed by a 1920's-built replica of an 1830's vintage engine with a 4-2-0 wheel arrangement, is significantly different from the actual engine. The real life Yonah, built in 1849, had a 4-4-0 wheel arrangement just as the General and Texas engines. Also, the Yonah had a cowcatcher, a headlight, and sand box, all of which the engine in the film lacks.
Factual error: As was the case in Buster Keaton's "The General" film, the General locomotive portrayed in the film more closely resembles the actual locomotive's 1893 appearance rather than its wartime appearance. As built, the General had three domes, an ankle bar on each side running the length of the engine, as well as the Western and Atlantic Railroad's then trademark strap-iron cowcatchers with horizontal slats. The engine was rebuilt in the 1870s, with the bars and third dome removed, and cowcatcher changed to the more conventional design seen in the film. The Radley Hunter Balloon stack the engine had was replaced with a diamond shaped one at this time, as the engine was converted to coal. The engine received a stack more closely resembling its original one in 1893.