The United States begins the secret project to develop the atomic bomb during World War II, with Oppenheimer as scientific director.
The first successful test of an atomic bomb is conducted in New Mexico, marking a major milestone in nuclear weapons development.
The United States drops the atomic bomb over Hiroshima, Japan, leading to massive destruction and loss of life.
A second atomic bomb is dropped on Nagasaki, Japan, resulting in Japan's surrender and the end of World War II.