The story structure is dramatic because it goes between three different realities--the present, the past and what is happening only in the main character's mind. The reader is confused which is real and which part is only in his mind.
At the beginning, before the reader sees the man actually being hanged, the past is introduced to the reader, as a sort of backstory. The backstory is set up in such a way as to elicit sympathy from the reader because the man was only a civilian who really wanted to help in the army but couldn't.
Next in the plot, when the the structure returns to the present, it appears as though the man escaped, which adds drama to the story because at that point the reader doesn't know it was only in his head. (Not until the end does it becomes apparent that he was only dreaming.)
At the beginning, a man, (Farquhar) is on a railroad bridge waiting to be hanged. He cannot move because his hands are tied and a noose is around his neck.
There are two different scenes on either side of the stream--one side is a forest and the other is a forte. This contrast is the writer's foreshadowing. It shows a contrast between freedom and war. The forest represents freedom and the fort represents war or death.
Soldiers form a line between the bridge and fort, all armed. When the captain gives a signal, a man will step off a board which will tilt down, and Farquhar will fall down to the stream between the boards and will hang.
The man Farquhar tries to think about his family but the sounds nearby become so loud he cannot think. He imagines how he could escape.
The story structure changes at that point to show the reader his past, that lead to him being hanged.
He was a Southern plantation owner who could not serve in the army. He wanted to however so when he met a Confederate soldier one night who stopped at his plantation he asked some questions about the war. The soldier told him that they were working on the railroad near Owl Creek Bridge. The Yankee commander said that anybody, even a civilian who tried to stop the building of the bridge would be killed. Later the soldier went by the plantation again,working as a scout for the Union Army.
The story structure comes back to the present as Farquhar falls between the railroad ties into the stream. He is unconscious. He regains his consciousness and splashes around in the stream. He realizes that the rope broke. He first goes to the bottom then comes up again and gets the ropes off his wrists. He takes in some fresh air and everything in sight crystallizes. He can see everything in sharp contrast--the fort, the soldiers who are pointing at him. A bullet almost hitting him.
He takes a dive missing a lot of bullets aimed at him. He comes up out of the water and he is downstream. A canon is fired but the forces of the water just push his out of harms way.He runs through the forest all day long and discovers a road that leads to his plantation.
He is walking, miraculously, even though his tongue is all swelled up and he is totally exhausted. His wife meets him on the porch.
He reaches out to embrace her, and feels an intense blow to the back of his neck. Farquhar suddenly sees bright white light and then there is only blackness. He is dead. His body is swinging from Owl Creek bridge.