The above information is wrong.
You can carry a tent, tent poles, and tent stakes without problems. TSA does not prohibit them, and I carry them all the time. For a non-hunting backpacker, just about the only things you may not carry on are:
1. Hiking poles -- must be checked.
2. Blades or Swiss army type multitools containing blade(s) -- must be checked.
3. Bear sprays -- must be checked (further restrictions apply)
4. Fuel -- liquid or gas -- cannot be carried on or checked. You'll have to buy your fuel at your ultimate destination. Note that a thoroughly cleaned stove is OK to carry on, as is one or two BIC lighters.
Click here for more details at TSA.