Given the sad state of public education, local history is just one subject that HS kids are generally ignorant about. But that doesn't mean a knowledge of history is not important. History is more than trivia and objective historical facts are more valuable than a feel good "heritage" based on misconceptions.
Now, if someone wore a Rebel Flag to represent the North, that would be a sign of historical ignorance. But I don't see it as being a sign of historical stupidity if a kid wears the flag to represent the South, just because he happens to do it in a county in the South where most people didn't want to secede. Some people there did want to secede, and lots of people have moved around. Not to mention that even the direct descendants of Unionists might feel some sympathy for the Confederacy after seeing the damage the federal government has done to our culture over the past few decades.
Heck, we're on the verge of having same-sex “marriage” foisted on us by the courts, using the Union-imposed 14th Amendment and the same “sociological” reasoning used in the Brown decision. It might be reasonable for a lot of people nationwide to start thinking more positively about the Rebel Flag.
Oh, I think history and local history is important, but how your county voted (versus your state or your region) seems pretty trivial. I had a junior high school teacher in the 60s who taught us a lot about local history (I went to school at Farragut, so I am local to you), but there were any number of things she didn’t teach us... one being how the secession vote went in the county. We understood East Tennessee was split and generally leaned toward non-secession, but once the war started, all of Tennessee was in the Confederacy. There were Tennessee units and East Tennessee units on both sides in the war.
Beyond that, I don’t think this kid’s decision on wanting to wear a confederate battle flag is based on the historical significance of what county he is in. It certainly wouldn’t be mine.