Dorothy Day was an American Catholic activist, writer, and co-founder of the Catholic Worker Movement. Her life was defined by her dedication to following the principles of the Sermon on the Mount, embracing radical hospitality, advocating for pacifism, and fighting for peace and social justice. Dorothy Day was strongly against the Vietnam War, criticizing it both morally and religiously. As a dedicated pacifist and Catholic, she believed the war was a serious injustice that went against the teachings of Christ. She saw the war as an example of imperialism and violence, which conflicted with her values of peace, justice, and helping the poor.