Which old Western is the inspiration for train scene in Dead Man?

I am interested in the scene in Dead Man in which the character is travelling West on a train. As he travels further west, the dress and type of passengers change to reflect this. My Dad says this is inspired by an old Western he saw in his youth, in which the main character takes a train West; he starts off being surrounded by besuited folk which gradually changes to Native Americans etc. But he can't remember what the original film is; can anyone help? Cheers!