I'd first recommend that you go back and take another look at the advice you got the first time you asked the question.

Having said that, you really need to take the first step here. You're basically asking, "what is there to do in the United States", and as if that wasn't an impossible enough task, you haven't told us a single thing about you and your interests. If you've seen the A-Z list of things to do in every state, then you have an idea of the vast number of things you could do - after all, even though that list contains more than 1300 things in the US alone - it just bareley scratches the surface of possibilities.

Some times the simplest starting point is the easiest. Get out your map, take a look at where you are going, and find some of thing things you want to do. If you've got an idea of what you want your trip to be, its going to be much much easier for others to start giving you other suggestion that will actually be helpful, and not just random ideas thrown against a wall.