World War II officially began on September 1, 1939, when Nazi Germany invaded Poland.

The Axis powers during World War II consisted of Germany, Italy, and Japan.

Adolf Hitler was the leader of Nazi Germany during World War II.

The United States entered World War II after the attack on Pearl Harbor by Japan on December 7, 1941.

The Allied invasion of Normandy in June 1944 was codenamed Operation Overlord.

The Battle of Midway in June 1942 is widely regarded as the turning point of the war in the Pacific.

The atomic bomb dropped on Hiroshima, Japan, on August 6, 1945, was codenamed Little Boy.

Germany surrendered to the Allies on May 8, 1945, while Japan surrendered on August 14, 1945.

The United Nations was formed after World War II to promote peace and cooperation among nations.

Over 60 countries participated in World War II.

Dresden, Germany, was heavily bombed by Allied forces during the war.

Auschwitz-Birkenau was the largest Nazi concentration camp and extermination center.

Dwight D. Eisenhower served as the Supreme Allied Commander in Europe during World War II.

The Japanese kamikaze pilots who carried out suicide attacks against Allied ships were known as Tokkotai.

Switzerland remained neutral throughout World War II.