The Great Depression broke some people, forged others, and left its mark not only on the United States but upon the entire world. It might have continued on indefinitely, but something happened to force America and other nations to deal with a greater threat.
Hitler had slowly but surely been marshalling his forces, moving in on nations such as Poland and others. Even in the early 1930s, far-seeing individuals understood Hitler's agenda and warned against him. The world paid no attention. Even when France and England were attacked, American allies, the United States stood back. On the other side of the world, Japan was committing attrocities against neighboring nations.
Only when Pearl Harbor was attacked in December of 1941 did America declare war on Japan. At that point, Hitler retaliated and declared war on America. The United States was officially at war. Factories now operated at full capacity, producing the materials needed to fight the battle of America's life.