World War I was a catalyst, altering the world's political landscape and leading to advancements in weaponry and tactics shaping warfare through the rest of the century. Perhaps its greatest influence, however, was on the lives of the soldiers who experienced the cruelest manifestations of this conflict. Their accounts demonstrate the impact of war on the individual and give us a glimpse of an otherwise unimaginable reality. In “Diary of a Doughboy,” by Pennsylvanian Harold W. Pierce of the Twenty-Eighth Division, we learn the emotional and psychological effects of war on one doughboy. Understanding these effects allows us to better understand humanity with regard to warfare.