Final answer:
Ambrose Bierce and Stephen Crane brought a new level of realism and naturalism to American fiction, offering a raw and authentic portrayal of the Civil War that contrasted with the idealized narratives of the time.
Step-by-step explanation:
Ambrose Bierce and Stephen Crane contributed to American fiction during the Civil War period by adding a layer of realism and naturalism that was distinctly different from the romanticized narratives of their predecessors. Unlike the romantic emphasis on idealizing nature and heroism, Bierce's and Crane's works incorporated elements of cynicism, graphic details, and psychological complexity to depict the harsh realities of war and the struggle for survival. Ambrose Bierce, known for his sardonic wit and dark view of human nature, often infused his Civil War stories with a realism that unveiled the brutality and trauma of war. His works sometimes veer into the surreal, reflecting the subjective experiences of individuals in traumatic situations. On the other hand, Stephen Crane, despite dying young, left an indelible mark on American literature through works like 'The Red Badge of Courage' that explored the psychological aspects of war.