Most Americans consider themselves part of the “middle class,” but no one can agree on what term that means. The problem? If sizing up the middle class is difficult enough, it’s even harder to say that circumstances within this group have changed. But they certainly have. As you’ll discover in this Fortune special report, life has gotten more difficult for the millions of people within the middle class. We dispatched more than 50 people to discover why the American dream has been fading for far too many.