I posted this question: What was the impact of 9/11
Basically what I'm wanting is, in what ways was the United Stated impacted, or what changed, because of the attack.
That is a very broad question. You could narrow it down considerably and it would still be a fairly broad question:
You might fill a book trying to answer any one of those; trying to answer all of them and more in the space of a single answer seems unlikely to succeed. On top of that, the question isn't bounded by a specific time-frame either, so the implication is that anything that changed between then and now should be considered.
My recommendation is that you try to focus a bit on what you need to know, describe what you're researching or curious about, and let the question follow from that.