Crane had read stories devoted to battles and people from the Civil War (which Crane himself never witnessed, having been born in 1871). He thought the stories reflected a dry, glorification of heroic deeds — but true emotions weren't expressed. "I wonder that some of those fellows don't tell how they felt in those scraps," Crane noted. "They spout enough of what they did, but they're as emotionless as rocks."
Inspired in part by Ambrose Bierce's own Civil War writings (Bierce noted we must "cultivate a taste for distasteful truths. And... endeavor to see things as they are, not as they ought to be"), The Red Badge of Courage was his attempt at showing the more human side of battle.
The novel follows a private in a fictional regiment taking part in an unnamed battle. True to his word, Crane focused on the emotions a soldier experiences. His main character, fearing failure, deserts mid-battle (though he later returns). Fear and anxiety are important and very real emotions in the book. For example:
In this last length of journey the men began to show strange emotions. They hurried with nervous fear. Some who had been dark and unfaltering in the grimmest moments now could not conceal an anxiety that made them frantic. It was perhaps that they dreaded to be killed in insignificant ways after the times for proper military deaths had passed. Or, perhaps, they thoughts it would be too ironical to get killed at the portals of safety. With backwards looks of perturbation, they hastened.