End of WarBeginning of Nuclear Age

Manhattan Project

Manhattan Project•June, 1942: Army Corps of Engineers led by Gen. Leslie Groves was appointed director

•Experiments were first held beneath University of Chicago’s abandoned Stagg Field (first controlled nuclear reaction took place)

•J. Robert Oppenheimer (theoretical physicist) directed Los Alamos research in New Mexico

•This was the most ambitious secret enterprise in history• More than 600,000 Americans were involved• Truman did not find out about it until he became

president

Truman and the Bomb

• Truman decides to use the Bomb because– Invading Japan would mean up to 1,000,000 more

casualties– Anti-Japanese sentiment is strong in the U.S.

• August 6, 1945 Enola Gay drops uranium bomb on Hiroshima

• August 9, 1945 Plutonium bomb dropped on Nagasaki

• Why these cities?– Were never hit by allied bombing

Hiroshima and NagasakiAugust 6, 1945 August 9, 1945

• President Truman’s decision

• Thought it would end the war and save American lives

• Hiroshima: 66,000-78,000 killed

• Nagasaki: 39,000 killed• Japan estimates

240,000 total

Japan Surrenders (V-J Day)

Japan surrendered onAugust 14, 1945

Formal signing took place on September 2nd aboard the Missouri

War Crimes Trials

• Nuremburg• 1945-46• 11 high Nazis executed• Others put in prison

• Tokyo• 1946-48• 7 Japanese leaders hanged• Premier Tojo hanged

May 8, 1945

August 14, 1945

MacArthur & U.S. forces occupy Japan

•Japan’s economy is reshaped – free market practices

•Japan had a new constitution (MacArthur Constitution)

• Established women’s suffrage

• Guaranteed basic freedoms

Memorable World War Two Images