What are the legacies of armed resistance? Why do some communities engage in armed mobilization in response to violence, disorder, and insecurity, while others under very similar conditions do not? Focusing on mobilization against organized crime in contemporary Mexico, we argue that historical experiences of armed resistance can have lasting effects on local preferences, networks, and capacities, which can facilitate armed collective action under conditions of rampant insecurity in the long run. Empirically, we study the Cristero rebellion in the early 20th century and grassroots anti-crime mobilization in Mexico during recent years. Using an instrumental variables approach, we show that communities that pushed back against state incursions almost a century earlier were more likely to rise up against organized crime in contemporary times.