United States Declares War on Germany

President Woodrow Wilson asked Congress for a declaration of war on Germany, citing unrestricted submarine warfare and the Zimmermann Telegram. The Senate voted 82-6, the House 373-50. Wilson framed American intervention in idealistic terms: 'The world must be made safe for democracy.' The US was militarily unprepared—its army numbered only 128,000 men—but eventually mobilized 4 million soldiers and provided the decisive material and manpower advantage to the Allies.