Hitler and the Nazi Party invaded Poland on September 1, 1939, and Britain and France declared war two days later.
Air raids were so common in Britain in 1940, it became part of daily life. When Germany decided to attack British air fields however, their bombing raid was shut down from the Battle of Britain. It showed Hitler wasn't invincible.
On December 7, 1941, Japan surprise attacked Pearl Harbor, sinking seven ships and killing over 2,00 men. The US declared war a day later, turning the economy into a war machine.
THE END OF THE WAR
The worst act of mass genocide in history was the Holocaust. Concentration camps like Auschwitz brought Jews in by train car and they were left to die, or be executed. Over 6,000,000 died.
On June 6, 1944, Canadian, British, and American stormed the beaches of Normandy in hopes of taking them over. It was a bloody battle, with around 2,000 troops on Omaha Beach dead. However, it began a campaign that started the liberation of Europe.
The first atomic bombs were dropped on Hiroshima and Nagasaki which killed over 130,000 people in August 1945. Even though the bombs ended the war, it started a conflict that lasted almost 50 years known as the Cold War between the USA and the USSR.