Why did some American oppose entering world war 1?

Some Americans opposed entering World War I due to a strong sense of isolationism, believing the U.S. should avoid entanglement in foreign conflicts. Others were concerned about the costs of war—both in terms of human lives and economic resources. Additionally, many Americans had ethnic ties to countries involved in the conflict, leading to divided loyalties and reluctance to engage in a war that did not directly affect them. Pacifist sentiments also influenced opposition, as some viewed war as fundamentally wrong.