During the 1920's the US economy experienced a major boom, making them one of richest countries during that period. However, there is a concept in economics that explains that as fast as one economy booms, is as fast it could suffer some consequences. Billionaires and millionaires started to appear, all living luxurious lives. A lot of industries were created, giving a lot of jobs. However, I'd quote Newton "for every action is an equal and opposite reaction", and thus, the Great Depression came to be. Not only the US was affected, it began a domino effect which led several economies into a major decline. Unemployment was very high, poverty even in rich countries became prominent. Germany, also became affected, and plus, they still had to pay the huge fine for causing WWI. During these times, Hitler rose to power, earning the sympathy of the German masses.