If you could go back in time and change anything about the 1920's, what would it be?

Of course, my answer will be different than yours, but I would have continued the Progressive-era legislation from the pre-WWI era.  Before WWI, America regulated the meat-packing industry, pharmaceuticals, and ended child labor.  America established national parks and ended several major monopolies.  America was attempting Prohibition, but that law was filled with problems before it left the halls of Congress--it was never meant to succeed.  After WWI, America voted in presidents such as Harding and Hoover--presidents who would have been more at home during the Gilded Age when we expected less of our presidents.  While it is dangerous to think of history as being filled with "what-if" scenarios, it is interesting to think about what would have happened if the Progressive Era would have continued past WWI.  America could have regulated the rampant speculation on Wall Street and put in a minimum wage for its most vulnerable workers.  America could have also provided for the elderly.  America did all of this anyway through the New Deal programs, but perhaps the nation would not have had to suffer a Great Depression which spread throughout the world and led to the rise of totalitarian governments in Italy, Germany, and Japan.