by Howard Zinn.
Joy Hakim's US History is pretty good - but a 15 yr would probably find it a bit dumbed down.
The Teaching Company has some excellent history tapes. Most are university level, but they have some high school level as well. From the Fertile Crescent to the (um? American Revolution? Civil War? I forget which event) is supposed to be EXCELLENT. (I have it here somewhere, but ds12 wants to finish his Egyptian History course first.) Teaching Company also has a second course about Am. History.
http://www.teach12.com/teach12.asp?ai=16281They're kind of pricey, but have pretty good resale value, too. You can get some on EBAY, but make sure you get the video tapes/DVD's instead of just the audio tapes.