The Great Depression affected most countries. Germany, still suffering from the effects of losing World War I, was hit especially hard.
Adolf Hitler achieved great popularity by blaming Germany’s troubles on minority groups, particularly Jews and Communists. In 1933, Hitler became dictator of Germany. He built up the German military with the intention of making Germany a world power through conquest.
In September 1939, Germany invaded Poland, starting World War II. The United States had pledged neutrality (not taking sides) but was eventually drawn into it. And it was war production, or making weapons and other materials for the military, that finally brought the country out of the Great Depression.