In The Great Train Robbery (1903), what type of train is held up by the outlaws?

In The Great Train Robbery (1903), the outlaws hold up a passenger train.

Edwin S. Porter's pioneering American short film follows a gang that forces its way onto a moving train, robs passengers and railway employees, and escapes before being pursued by a posse. The train robbery is the film's defining action and supplies its title.

The movie is often described as one of the earliest narrative Westerns, although it draws on stage melodrama, news reports, and earlier train-robbery pictures. Its famous final shot of an outlaw firing directly toward the camera is not part of the story's chronological action. Viewers sometimes call the target a mail train because mail cars were frequent targets in real robberies, but the film clearly depicts a passenger train carrying people and valuables.