Military Involvement:
1. Entry into the War: The US officially entered World War 2 on December 8, 1941, the day after the attack on Pearl Harbor by Japan.
2. Pacific Campaign: The US and its allies fought against Japan and its allies in the Pacific. American forces engaged in major campaigns such as the battles of Midway, Iwo Jima, and Okinawa.
3. European Campaign: The US provided significant support to the Allied forces in the European theater. American troops landed in Normandy on D-Day in June 1944 and fought alongside British, French, and other Allied armies.
4. Strategic Bombing: The US launched strategic bombing campaigns against Germany and Japan, targeting military installations and industrial centers.
Diplomatic Efforts:
1. Lend-Lease Program: The US implemented the Lend-Lease program, through which it provided military equipment and supplies to Allied nations.
2. Allied Conferences: American leaders participated in key conferences, such as the Casablanca, Tehran, Yalta, and Potsdam conferences, to coordinate Allied strategy.
3. United Nations: The US played a key role in the establishment of the United Nations, an international organization aimed at maintaining peace and security after the war.
Technological Contributions:
1. Manhattan Project: The US led the Manhattan Project, which successfully developed the atomic bomb. The atomic bombs dropped on Hiroshima and Nagasaki in August 1945 ultimately brought about Japan's surrender.
2. Codebreaking: American codebreakers, notably at Bletchley Park in the UK, made significant contributions to cracking enemy codes, providing crucial intelligence to the Allies.
3. Industrial Production: The US became the "Arsenal of Democracy," mass-producing ships, aircraft, weapons, and other military equipment.
Leaders and Key Figures:
- President Franklin D. Roosevelt led the US throughout most of the war.
- General Dwight D. Eisenhower served as Supreme Allied Commander in Europe.
- General Douglas MacArthur led American forces in the Pacific.
Overall, the United States played a vital role in the Allied victory in World War 2, contributing both militarily and diplomatically to the defeat of the Axis powers.