Mainstream opinion, whether from public health officials or op-ed writers, has a simple response to controversies over vaccination. Those who favor vaccines are enlightened. Those who express skepticism are deluded and dangerous. Yet conflicts over immunization in American history are much more complex–and interesting–than this simplistic narrative would suggest. For one thing, such conflicts actually pre-date both the nation and vaccination, going back to vicious and nearly deadly struggles over inoculation during in Puritan Boston. Moreover, recent historians have compellingly argued that vaccine dissenters have, not infrequently, offered perspectives on medicine and politics that have actually expanded liberty and democracy. I seek to extend this basic insight. I do not question that portions of the historical anti-vaccination movement have been radically anti-science as well as anti-civil libertarian (think Dr. Strangelove and bodily fluids). Yet vaccine dissidents’ commitments to bodily autonomy, and to a broad conception of populism, have also informed democratic struggles–from resistance to slavery to immigrants’ rights, from Progressive Era fights against monopoly to feminist movements to expand women’s control over their own bodies. Historians often do their best taking seriously even the most marginalized or seemingly benighted voices. We should not allow presentist lenses, or a facile spirit of condemnation, to miss the complexity of the fascinating range of past debates over vaccination in American history.