The Axis powers are finally defeated in 1945—Nazi Germany in May and Imperial Japan in August. 

 The "Manhattan Project," the largest, most secretive wartime project in history, explored the possibility of splitting the atom to create an "atomic bomb."

On June 6, 1944, the Allies launched the long-anticipated invasion of Normandy, France. Soldiers from the United States, United Kingdom, Canada, and other Allied nations faced Hitler's formidable Atlantic Wall as they landed on the beaches of Normandy.

On May 8, 1945, thousands of people took to the streets in cities around the world to celebrate news of Germany's surrender and the end of World War II in Europe. 

On April 1, 1945, more than 60,000 soldiers and US Marines of the US Tenth Army stormed ashore at Okinawa, in the final island battle before an anticipated invasion of mainland Japan.