From John L. Chapman and Karl-Henrik Smith, RealClearDefense: “Today is a historical marker of immense importance in American history: it is the centenary of American entry into the Great War, later known as the First World War. One hundred years ago today, on April 6, 1917, the United States declared war on Germany, following strong majority votes in both Houses of Congress and the impassioned speech of President Woodrow Wilson to a joint session on April 2, wherein he asserted that America must fight in the European war “to make the world safe for democracy.”"
European Security at the End of American Century
From Jeffrey Mankoff, War on the Rocks: “The American century began, in a sense, 100 years ago today. On April 6, 1917, the House of Representatives voted to declare war on Germany two days after the Senate had done so, and the United States joined the Allied side in World War I. Over the next year and a half, American troops helped turn the tide of the war in bloody battles at places like Chateau-Thierry, Saint-Mihiel and the Meuse-Argonne.”