World War II was a major historical event in American 20th-century history. The United States entered into the war at the end of in 1941, after the Pearl Harbor attack by the Japanese imperial navy. The end of the conflict, that happened with the drops of the first nuclear bombs over Hiroshima and Nagasaki, marked the beginning of the United States as a military superpower. It was also the start of the Cold War.
The Cold War was important in American History for many reasons. The United States faced armed conflicts on many fronts during the Cold War, like the war of Korea or the war of Vietnam, in which many American soldiers died. Also, It was characterized by the nuclear race between the United States and the USSR, which extended the fear of nuclear warfare among the civil population. The space race was another relevant episode of the Cold War, that took the two superpowers to develop rocket science and send satellites, animals, and astronauts to the outer space. This race was won by the US in 1969 when NASA put the first man on the moon.
During this time, there was a large counterculture movement in the United States that responded against the Vietnam War, the nuclear race, the consumerist culture, it fought for the civil rights of Afro-American citizens, women, and other minorities. It shaped social movements and the hippie wave of the second half of the 20th century.
