What is the effect of the narrator remaining unnamed until later in the story?

Ambrose Bierce's story "An Occurrence at Owl Creek Bridge" has an unusual form. The man being hanged is not identified in Part I. Then in Part II, after the man has fallen from the bridge with the noose around his neck at the end of Part I, Bierce uses a flashback to fill the reader in on all the important questions. By not identifying the condemned man in Part I, Bierce gets stronger reader identification with the his thoughts and feelings. The story opens with these significant words:
A man stood upon a railroad bridge in northern Alabama, looking down into the swift water twenty feet below.
If Bierce had identified Peyton Farquhar in Part I, as he does in Part II, the reader would feel that this hanging was happening to someone else. But by making him anonymous, Bierce makes the reader feel that he or she is the person being hanged. Then when the exposition, which makes up all of Part II, reveals all the necessary information about the protagonist, the reader stays strongly identified with Farquhar in spite of the fact that the reader may have no sympathy for the Confederate cause or for slave-owners. This would have been a more important consideration at the time the story was published, which was over a hundred years ago. The reader remains identified with Farquhar to the very end because he or she shares his motivation to stay alive and get back home and is held strictly in Farquhar's point of view.