Going through the links, one finally finds out that the passage is being read in English class. In that context, it makes some sense to stay on the subject and not cover history questions.
No it doesn't.
Knowledge cannot be compartmentalized into "subject" groups. True knowledge encompasses many disciplines and must be put into context with all other knowledge. This is a shallow example but one that comes readily to mind.... you can read a recipe for apple pie, but you can't possibly comprehend what an apple pie is if you do not have any idea what an apple is.
Back when I taught Elementary school in the 70's, we went to great lengths to coordinate the different subjects so that a particular lesson could be taught "cross-platform" so-to-speak, and encompass math, history, science, language, literature and perhaps even P.E. It made the lesson more real to the students as they could see that it touched them in many ways and had many applications in their lives. We used to sit in grade-level department meetings and come up with ideas of how we could achieve this.
But, you must understand that if people today are too knowledgeable about a particular subject, for instance an historical event, then it will be too difficult for government propagandists to rewrite the facts to their own evil benefits. It would be too difficult for them to redefine Lincoln's words to mean something entirely different.