It has been just over three years since the Supreme Court instructed lower courts to evaluate Second Amendment challenges by examining history and tradition. And it is no secret that the courts have struggled. Overwhelmed by the task of evaluating historical claims, lower courts instead are turning to other judges as authorities on history. They are using what Larsen calls in this article “historical precedents”—meaning language about history from an older decision that the subsequent judge then treats as authority, not as part of the legal rule but as truth of the matter asserted. This practice presents a very interesting puzzle: once the Supreme Court blesses a historical source or a historical narrative, does that conclusion—in and of itself—bind other courts to the same answer about what happened in the past? The question is more than just an academic head scratcher. It creates significant practical concerns. The Supreme Court is not designed to be a factfinding institution, nor are the Justices trained historians. They can make mistakes, or our understanding of the history can change, and in any event some language that recites historical claims—particularly when appearing in separate opinions—is not contemplated with the kind of spotlight and scrutiny that comes when a legal rule is debated. These realities make entrenching historical precedents throughout the judicial hierarchy a risky endeavor.