At the summary states, this film truly made an unusual casting decision by casting Burt Lancaster as a Hispanic man. At first, this made me groan, but after a short time I realized that he did a pretty good job with the accent and there are many light-skinned Mexicans, so it wasn't too hard to believe this. The only negative about this is that the film is in many ways about race prejudice and you wonder if maybe casting an Anglo in such a role that it might be undermining the central message. Regardless, the film is several notches above the usual Western.
It begins in the Old West with sheriff Lancaster being called in to arrest a man holed up in a shack with his odd woman. The man inside is killed by Lancaster and then it's discovered that the man was NOT the wanted man, but totally innocent. Lancaster feels bad about this and tries to take up a collection to help the lady but no one seems to care. In particular, the rich land owner who insisted the guy in the shack WAS guilty felt no compunction to help at all. This angered Lancaster, but the rich guy said that he could care less since the dead man was Black.
The rest of the film consists of Lancaster spending the rest of the movie trying to force the rich guy to contribute his share. However, the rich guy responds by having Lancaster beaten and humiliated--and in the process unleashing retribution from Lancaster, who begins killing off the land owner's posse as they chase him across the Southwest.
Despite the simplicity of the plot, the film never got dull nor did it seem overly preachy. Also, the film ended very well, though I don't want to spoil anything by saying more about it. An intelligently written script, good acting and direction make this film a winner.