How did World War II change the United States internationally, and domestically?
World War II produced the United States as global superpower and defender of capitalism and democracy in the world. European nations that were world powers before the war (Germany, Italy, United Kingdom and France) were totally destroyed by warfare. Their infrastructures, homes, economic systems, and social systems were destroyed. While the United States suffered over a million casualties throughout the course of the war, its economy was robust and its military largely unscathed. Many in the American government felt that it was strategically important to help other countries to recover from the war. Internationally, the United States offered billions of dollars of aid to the countries of Europe and established an alliance of countries through NATO to ensure their security. There was a shift in thinking about America's role in global politics. The newly formed United Nations was located in New York City and the U.S. became a major player in the organization. Because of the Allied victory in World War II, there were only two superpowers that survived, and the United States was one of them.
World War II also had a dramatic effect on the United States domestically. The sense of confidence that existed cannot be quantified, but was very evident. There was a sense of prosperity as Americans moved to the suburbs and an interstate highway system was born. Nuclear power, which was developed for military use, was applied for a more peaceful purpose as electric companies built nuclear reactors to produce electricity. Many social changes were on the horizon in the United States. As an example, African-Americans, who had fought so valiantly in the Allied victory, pressed for their rights at on the homefront. The prosperity of the 1950's allowed the growth of popular culture as many Americans bought a television and listened to rock and roll on their radios.
While World War II had the effect of destroying many countries, the United States matured into a political and economic superpower because of it.