What part of the american economy did not enjoy prosperity in the 1920s?

  Many factors played a role in bringing about the depression; however, the main cause for the Great Depression was the combination of the greatly unequal distribution of wealth throughout the 1920's, and the extensive stock market speculation that took place during the latter part that same decade. The maldistribution of wealth in the 1920's existed on many levels. Money was distributed disparately between the rich and the middle-class, between industry and agriculture within the United States, and between the U.S. and Europe. This imbalance of wealth created an unstable economy. The excessive speculation in the late 1920's kept the stock market artificially high, but eventually lead to large market crashes. 

These market crashes, combined with the maldistribution of wealth, caused the American economy to capsize ... the rewards of the "Coolidge Prosperity" of the 1920's were not shared evenly among all Americans. According to a study done by the Brookings Institute, in 1929 the top 0.1% of Americans had a combined income equal to the bottom 42%. That same top 0.1% of Americans in 1929 controlled 34% of all savings, while 80% of Americans had no savings at all...In the 1923 case Adkins v. Children's Hospital, the Supreme Court ruled minimum-wage legislation unconstitutional ...Essentially what happened in the 1920's was that there was an oversupply of goods. It was not that the surplus products of industrialized society were not wanted, but rather that those whose needs were not satiated could not afford more, whereas the wealthy were satiated by spending only a small portion of their income.

B. marbury v madison