After World War I, the economy soared, so much so that historians called the 1920s the "Second Industrial Revolution." The economy of the 1920s was a fundamental change as it led to new mass production, mass consumption and set the stage for the looming Great Depression. The 1920s saw a major boom in mass production that allowed lower prices for technological products. This decade was characterized by a huge expansion of consumer credit, in which Americans became accustomed to financing the purchase of new products, such as the growing popularity of automobiles and radios, which were created by mass production. The automobile, film, radio and chemical industries skyrocketed during this decade: one of the most important was the automobile industry. When Henry Ford churned out production automobiles, approximately 1.9 million were sold by the end of 1929. The economy of the auto company had a great impact not only on business, but also on society. Henry Ford, who had revolutionized the new workers' day and the concept of mass production, had indirectly influenced the way Americans lived and behaved. Automobiles have fueled the growth of other markets, such as steel, rubber, glass and oil. It also promoted urban and suburban growth, where a new class of Americans was emerging. Now citizens could go to new places, meet new people, act differently... etc... The speed with which mass-produced products spread in America was astonishing: not only cars but also washing machines, refrigerators, irons ironing, electric and gas stoves - a whole series of inventions and technologies that have significantly transformed that part of economic life that takes place within the family. However, this change and the growth of the American economy had an important consequence. In fact, one of the major consequences of mass production was the accumulation of stocks of capital goods for internal production. And that, of course, was the biggest key change… because it seemed like the stock market and rising industry of the 1920s would last forever. This stock market rally led to the Great Depression… a downward spiral of economic depression. The economic boom of the 1920s led to the Great Depression. It has affected almost the entire industrialized world. The primary cause of the Depression was the unequal distribution of wealth during the 1920s and the extensive stock market speculation that took place during the latter part of the same decade. The maldistribution of wealth in the 1920s existed on many levels.