world war 1 By mlopez1 Jun 28, 1913 assassination of archduke franz ferdinand the day he passed away. Aug 4, 1913 american neutrality in world war 1 allowing u.s. to stay out of a European conflict for as long as . Sep 5, 1918 the battle of the marne halted the german advance into france , saved paris , and ended germany's plan for a quick victory in world war 1.