On June 28, 1919, the Treaty of Versailles formally ended World War I. Although the U.S. helped negotiate the treaty, the Senate refused to ratify it. The refusal kept the United States out of the League of Nations. The debate reflected differences over America’s role in global affairs. The treaty shaped interwar geopolitics in Europe. As a result, June 28 became a date deeply connected to international diplomacy and American foreign policy debates.
