What purpose does the Federal officer’s point of view serve in the story? (horseman in the sky)

The Federal officer's  point of view provided with an insight into the character's experience before revealing the true depths of his choice.

Explanation:

Ambrose Bierce in the story "A Horseman in the Sky" has used the third person omniscient point of view. The Third Person Omniscient point of view is the one in which the narrator is omniscient (is not a part or character of the story) but knows the thoughts and feelings of all the characters.

Ambrose creates a shift in this point of view at the end of the story when the story is told from the federal officer's point of view. This shift in the point of view helped the readers to know the thoughts of the character's experience before revealing the truth. The federal officer in the story saw the horseman falling down the cliff which he picturized as a beautiful horse looking like it is flying. The flying horseman is compared to some new Apocalypse found in the apocalyptic book of Apostle John. This comparison reveals the end times stated in the book of Revelation.