In this article, I examine how 9/11 and the subsequent efforts to combat terrorism have affected what people know about politics. My analysis suggests three main differences between knowledge before and after 9/11. First, knowledge of 9/11 and the “war on terrorism” shot up to uncommonly high levels, just as common sense and our theories would predict. The second point is less intuitive: Heightened interest spread to issues not directly related to the terrorist attacks and appears to have increased knowledge of politics more broadly. Finally, a comparison between knowledge related to 9/11 and general political knowledge reveals that some of the usual obstacles to learning did not matter in the aftermath of 9/11. A low sense of civic duty, lack of faith in government responsiveness, and a full-time job all kept people from getting informed about politics in general, but not from learning about the terrorist attacks and the war on terrorism.