The train is coming from the east, bringing new people who will swell the population of the West and make radical changes. The train symbolizes civilization and progress, swift and unstoppable. It contains the kinds of amenities that are part of the civilization of the eastern United States and of Europe but were unknown in the West until rapid transportation became available. The year is around 1897. The speed of the train in comparison to the old wagons drawn by horses or oxen is like the speed of light. The train is carrying people from east to west, but it will not be carrying many people from west to east. The tide of immigration is always westward. And with the advent of rail transportation following the Civil War, that tide of immigration of had grown and accelerated. This train will be stopping for water at a little Texas town destined to undergo the same transformation that is happening all over the Wild West.
Crane's description of Jack Potter's wife is significant.
The bride was not pretty, nor was she very young. She wore a dress of blue cashmere, with small reservations of velvet here and there and with steel buttons abounding.
Women themselves were rare enough in many parts of the West, and the kind of outfit this bride is wearing will amaze the inhabitants of Yellow Sky, including Scratchy Wilson. It represents propriety, culture, refinement, civilization. Crane specifies that the bride is not pretty or very young. Girls who were young and pretty did not need to come out to the West to find husbands. But homely girls who wanted to get married and have babies, and who felt themselves getting older, knew that they would find themselves sought after by the lonely men in the West. The big, safe, comfortable trains were making it possible for single women to travel west in growing numbers.
The theme of Stephen Crane's story has to do with the fact that it was the arrival of respectable women that tamed the Wild West. They wanted marriage and babies. They also demanded propriety, civilized behavior, sobriety, schools, churches, and the kinds of things such as pianos and fancy furniture that had to be imported from the East. It is significant that the bride's husband is the town marshall of Yellow Sky, because while he is bringing civilization with her, she is bringing law and order with him. She has already gotten him to look and feel different in his "new black clothes."
From time to time he looked down respectfully at his attire. He sat with a hand on each knee, like a man waiting in a barber's shop. The glances he devoted to other passengers were furtive and shy.
He isn't carrying a gun--but he doesn't need a gun to deal with Scratchy Wilson when they unexpectedly come face to face on the street. Scratchy is a symbol of the Wild West. He is tamed right on the spot by one look at the sheriff in his new black suit and the bride in her blue cashmere dress with
. . . puff sleeves, very stiff, straight, and high.
Scratch's final words to Jack have a double meaning.
"Well," said Wilson at last, slowly, "I s'pose it's all off now."
The feud between the two men is all off now, and the wild behavior of men like Scratchy Wilson is all off too. It is noteworthy that the bride does not say a single word during the confrontation between Scratchy and the town marshall. He is defeated by her mere appearance and everything she represents.