"Was the American Revolution revolutionary?" holds a classroom for a month. "When was the American Revolution?" holds it for four seconds. The difference is not topic — it is structure.
Three properties of essential questions
1. They are genuinely debatable. Reasonable people, looking at the same evidence, can land in different places. That disagreement is the engine of the unit.
2. They require evidence to answer. An opinion prompt ("What do you think about…?") invites vibes. An essential question forces students back into the sources.
3. They matter beyond the classroom. Students can hear the question echo in the news, at the dinner table, in their own decisions.
A quick test
Write your candidate question, then try to answer it in one sentence. If you can — and your colleagues would all write roughly the same sentence — it is a quiz item, not an essential question. If your one-sentence answer immediately makes you want to add "but on the other hand…", you have found one.
