Step-by-step explanation:
World War 2 was one or the most tragic events of United States causing many changes in how the country is now. The United States in around 1938 didnt make weapons much because they didnt go to war but in 1943 the United States starting making more then 2x the production that any country was making. They started focusing more in military power causing the nation to become the most powerful in the world. New medicines and ways of medical treatment were discovered helping the medical department improve a lot. World war 2 helped us change a lot from a country without fire weapons to having fire weapons anywhere.