Pivotal battles during the American Civil War, such as Gettysburg and Antietam, significantly shifted public perception regarding the conflict's legitimacy and necessity. These battles not only demonstrated the war's high human cost but also intensified debates over slavery and national unity. The Union's victories provided momentum for the Emancipation Proclamation, transforming the war into a moral cause against slavery. As the battles unfolded, public opinion became increasingly tied to the ideals of freedom and democracy, reshaping the collective narrative of the nation. This influence continued to resonate in American society and culture long after the war ended.