How did Henry Fleming earn his war injury?

Henry Fleming, the protagonist of Stephen Crane's "The Red Badge of Courage," earns his war injury during a battle in which he becomes overwhelmed by fear and confusion. Initially, he flees from the fighting but later, after witnessing the chaos around him, he is struck in the head by a panicked soldier's rifle. This injury becomes symbolic of his internal struggle and growth, as it forces him to confront his cowardice and ultimately seek redemption.