The Date

The opening sequence of this movie released in 1952 and based on the 1948 novel by Herbert Childs, claims that the Argentine Pampa of "75 years ago" and the life of the old time gauchos has disappeared.

Thus "75 years ago" might have been about 1873-1877. The movie is partially about the ending of the gaucho way of life as the Argentine government takes more and more control over the Pampa, And so it might happen sometime in the period after when the gaucho way was still strong about 1873-77.

In my guess, since the protagonist is given the choice between prison and service in the Argentine army on the Pampa, the date might be about, say, 1875-1885, or so, during the Argentine "Conquest of the Desert".

The synopsis in the IMDB page says: "Set in the Argentina of about 1875 in which a customary punishment for killing was a sentence to army service..."

And the synopsis on this very page says: "In 1875 Argentina,..."

So other people share my estimate of the fictional date. Someone who has actually read the novel, and someone who knows something about Argentine history, should be able to give perhaps a more accurate idea of the fictional date.

By the way, anyone who knows anything about how the United States US army recruited during the 19th century will have to agree that the Argentine army in this movie seems a bit more tyrannical and harsh.