"Most histories regard The Great Train Robbery as the first Western, initiating a genre that was in a few short years to become the most popular in American cinema. Made by the Edison Company in November 1903, The Great Train Robbery was the most commercially successful film of the pre-Griffith period of American cinema and spawned a host of imitations.
What is exceptional about Edwin S. Porter's film is the degree of narrative sophistication, given the early date. There are over a dozen separate scenes, each further developing the story. In the opening scene, two masked robbers force a telegraph operator to send a false message so that the train will make an unscheduled stop. In the next scene, bandits board the train. The robbers enter the mail car, and, after a fight, open the safe. In the following scene, two robbers overpower the driver and fireman of the train and throw one of them off. Next the robbers stop the train and hold up the passengers. One runs away and is shot. The robbers then escape aboard the engine, and in the subsequent scene we see them mount horses and ride off. Meanwhile, the telegraph operator on the train sends a message calling for assistance. In a saloon, a newcomer is being forced to dance at gunpoint, but when the message arrives everyone grabs their rifles and exits. Cut to the robbers pursued by a posse. There is a shoot-out, and the robbers are killed.
There's one extra shot, the best known in the film, showing one of the robbers firing point blank out of the screen. This was, it seems, sometimes shown at the start of the film, sometimes at the end. Either way, it gave the spectator a sense of being directly in the line of fire.
One actor in The Great Train Robbery was G.M. Anderson (real name Max Aronson). Among other parts, he played the passenger who is shot. Anderson was shortly to become the first star of Westerns, appearing as Bronco Billy in over a hundred films, beginning in 1907.
In later years some have challenged the claim of The Great Train Robbery to be regarded as the first Western, on the grounds either that it is not the first or it is not a Western. It is certainly true that there are earlier films with a Western theme, such as Thomas Edison's Cripple Creek Bar-Room Scene (1899), but they do not have the fully developed narrative of Porter's film. It's also true that it has its roots both in stage plays incorporating spectacular railroad scenes, and in other films of daring robberies that weren't Westerns. Nor can its claim to being a true Western be based on authentic locations, because The Great Train Robbery was shot on the Delaware and Lackawanna Railroad in New Jersey. But train robberies had since the days of Jesse James been part of Western lore, and other iconic elements such as six-shooters, cowboy hats, and horses all serve to give the film a genuine Western feel."
Taken from '1001 Movies You Must See Before You Die'.