The jazz age brings to mind flappers and sporty roadsters. Then comes the Great Depression, with its breadlines and shantytowns crowded by men without jobs. These are newsreel images, grimly intelligible but weightless until we imagine the shock of sudden, massive economic disaster in a nation that understood its prosperity as a benefice ordained by history in concert with nature. Not every member of the middle class descended into poverty. Those who did carried with them a burden of fear and humiliation they never expected to bear. They found out what it was to be unwanted.