The revolutionary American poet known for her stark reflections on war and peace is Walt Whitman. Though widely recognized for his contributions to American literature, his poetry often delved into profound themes related to the human experience during times of turmoil. Whitman's work during the Civil War demonstrated a keen awareness of the emotional and physical devastation wrought by conflict, emphasizing themes of unity and healing in the aftermath of violence. His groundbreaking collection, "Leaves of Grass," captures the nuances of life, love, and mortality, establishing him as a pivotal figure in American poetry.