World War II
Read this article on the U.S. experience in World War II. In addition to covering many of the social aspects of the war, it also considers the U.S. entry and its experience in each theater of war.
Conclusion
The United States entered the war in a crippling economic depression and exited at the beginning of an unparalleled economic boom. The war had been won, the United States was stronger than ever, and Americans looked forward to a prosperous future. And yet new problems loomed. Stalin's Soviet Union and the proliferation of nuclear weapons would disrupt postwar dreams of global harmony. Meanwhile, Americans who had fought a war for global democracy would find that very democracy eradicated around the world in reestablished colonial regimes and at home in segregation and injustice. The war had unleashed powerful forces that would reshape the United States at home and abroad.