Eddy duziri Ngalaba nke 9 na mbido nke Operation Overlord, aha nzuzo maka Agha Normandy, na-agbadata na Utah Beach ụbọchị anọ ka ụbọchị D-Day nke June 6, 1944 gasịrị. N'ihi ọrụ ya n'iweghara ọdụ ụgbọ mmiri French nke Cherbourg, e nyere Eddy Cross Distinguished Service Cross. N'ọnwa Ọgọstụ, ọ ghọrọ Commanding General nke XII Corps, nke na-abụkarị onye isi nke Lieutenant General George S. Patton's Third United States Army. Eddy duziri XII Corps na ọganihu ndị Allied site na Paris ruo Rhine
nakwa n'agha ndị ọzọ a lụrụ n'Ebe Ọdịda Anyanwụ Ụwa. N'oge Agha nke Bulge, Eddy's XII Corps nwere ihe ịga nke ọma na-akwado ubu ndịda nke German salient. N'ọnwa Eprel afọ 1945, mgbe o sonyere na mwakpo ndị Western Allied na Germany, obere oge tupu njedebe nke Agha IIwa nke Abụọ na Europe, Eddy laghachiri na United States n'ihi ọrịa siri ike (ọrịa ọbara mgbali elu, nke ọ gbakere) ma dochie ya na ndị isi nke XII Corps site n'aka Major General Stafford LeRoy Irwin.