Describe how the war is involved in the story an occurrence at owl creek bridge

The setting of the Civil War is intrinsic to the plot of
Ambrose Bierce's story, "An Occurrence at Owl Creek Bridge." Without this war, there
would have been no soldier for Peyton Farquhar to have learned about the bridge from;
the Federal scout, as he was later revealed to be, would never have been in Alabama. 
There, then, would never have been any motive for Farquhar to blow up the bridge had
there been no Civil War.  And, there would have been no
story.

The war, therefore, is absolutely essential to the
plot.  For, it provides Farquhar the romantic motivation to be heroic.  He departs from
his family only for something greater: his love of country.  He, then, becomes the
sacrificial victim to a cause, hanged, swinging gently and senselessly from side to side
beneath the boards of the Owl Creek bridge.  Within the setting of the war, Peyton
Farquar is an object of satire: He has died because of his Romantic notions of
war.