The Second World War broke out in September 1939 after the Polish invasion by Adolf Hitler and which caused Great Britain and France to declare war with Germany. This Second World War would last for the next six years and sadly, would cause more deaths than any other earlier wars. The Holocaust was born out of this period by Hitler in which he had 6 million Jews murdered in Nazi concentration camps. The rest of an estimated count of 45-60 million people were killed in this war. Hitler’s plan had two objectives; invade the Soviet Union and the extermination of the Jews throughout the German-occupied Europe.

German forces took over Belgium and the Netherlands in a "blitzkrieg" or lightening war. After 3 days, Hitler's troops had broken through all defense barriers and the British Army realizing defeat, quickly evacuated at the end May by sea. The Italian dictator Benito Mussolini declared war with France. With France on the verge of collapse, Henri Philippe Petain with his new government asked for a truce only two days after German forces entered Paris. The British Armed Forces battled with the German forces in the famed Battle of Britain, and Hitler was forced to postpone his invasion plans.

On December 7, 1941, Japanese aircraft attacked a US naval installation on Pearl Harbor in Hawaii. Taking the lives of more than 2,300 troops, the Americans approved entering the Second World War. On December 8, the war on Japan was declared by the US Congress. Germany and other Axis Powers declared war on the United States.

In June 1942, the Battle of Midway was won by the US Pacific Fleet and by mid-1943, Allied Naval Forces moved on Japan using a series of "island-hopping" attacks.

By 1943, American and British forces defeated the Germans and Italians in North Africa. The invasion continued in Italy and Sicily, causing the Mussolini government to fall by July 1943. The fighting would continue between the Germans and Allied fighters until 1945.

On the Eastside, a counteroffensive by the Soviets in November 1942 ended the Battle of Stalingrad, which was some of the fiercest and bloodiest battles of the war. With very low food and medical necessities, the Germans laid down their weapons on January 31, 1943.

On June 6, 1944, D-Day, the Allied began a huge invasion of Europe. British, Canadian and American soldiers totaling 156,000 troops stormed the beaches of Normandy, France. Hitler drove the British and Americans back from Germany, known as the Battle of the Bulge from December 1944-January1945. Hitler took his own life on April 30, 1945 in his bunker in Berlin and the Germans surrendered on May 8.

Heavy casualties in both Iwo Jima (February 1945) and Okinawa (April-June 1945) led US President Harry Truman to authorize the use of a new weapon, the atomic bomb, on the 2 Japanese cities of Hiroshima and Nagasaki in early August. This devastating bomb caused the Japanese government to surrender on September 2, 1945 and ending the Second World War.