Calvin Coolidge's administration had also added to the problem. Coolidge supported business and the wealthy that invested in it. He signed the Revenue Act of 1926 that lowered federal income and inheritance taxes. The Secretary of Treasury at the time, Andrew Mellon, was a main influence in cutting taxes, and he was able to lower federal taxes. The Supreme Court even worsened the situation by ruling that minimum wage legislation was unconstitutional in the 1923 case of Adkins vs. Children's Hospital.
Americans invested in the stock market during the late 1920s for numerous reasons. Rising stock dividends was one cause. New investors entered the market thinking they could "get rich quick". There was an unbroken cycle of new investors coming in and old investors leaving that kept new money flowing. .
Another reason for the investment was that at this time, banks made money easily accessible at low interest rates. It is possible that many people took out loans not only to buy homes and automobiles, but also to buy stock. Also, more Americans had extra money due to higher wages that they could invest. Magazines, such as Ladies Home Journal, helped promote the stock market to the American public. In an article titled "Everybody Ought to be Rich", John Jacob Raskob, Chief Executive of General Motors and head of Democratic National Committee, suggested that every American should invest fifteen dollars a week in common stocks.
During this time, industry was producing far more than what was needed and businesses were using their profits on new machinery and more workers, which in turn, increased the overproduction problem. This excess of manufacturing gave Americans a sense of security in business, which encouraged them to buy more stock. .
An additional motive for investors was that the stock market had no effective legal guidelines on buying and selling stock. Because of this, corporations began printing up a surplus of common stock and investors bought stock on credit.