Authenticity is a central, defining feature of the practice of historical reenactment. The authenticity practices employed by reenactors have a powerful impact on the kinds of historical narratives used in reenactment and are strongly related to reenactors’ claims about how they experience the past. Reenactment groups carefully curated their living history encampments at public events and offered pop-up outdoor museum experiences. Ethical questions surrounding the performance of unpalatable pasts surfaced more dramatically in more public or officially sanctioned reenactments, in particular in living history museums. Reenactors’ attachment to authenticity as an embodied physical experience of the past has often been overstated by critics of the practice and by traditional historians in particular. The goal of authenticity has created other unexpected problems for reenactors, whose recreated objects are intentionally newly made and do not exude the qualities of pastness that audiences crave.