September,1942- A decisive battle was fought at February,1943 Stalingrad,which was the turning point of the war. December,1941 The U.S.A.entered the war after the Japanese planes bombed the American naval base at Pearl Harbor.September, 1942 — February, 1943 A decisive battle was fought at Stalingrad, which was the turning point of the war. December, 1941 The U. S. A. entered the war after the Japanese planes bombed the American naval base at Pearl Harbor