What happens when states invest to acquire systematic information on citizens? Building land cadasters is an important way through which historical states have attempted to collect taxes more efficiently and to enforce property rights. However, there is little rigorous empirical evidence on the consequences of cadasters when they were first created. I analyze the French Napoleonic cadaster, an ambitious land surveying project with the initial goal of improving the fairness of the fiscal system, which took almost 40 years to complete in a context of contentious state-society relations. I build a novel dataset of the gradual roll-out of the cadaster in 2,697 cantons and combine it with data on local administration, fiscal capacity, and state-society relations. First, I show that the French state chose to consolidate existing fiscal capacity rather than to extend its reach to remote areas. Perhaps because of this cautious approach, I find no evidence of a backlash by wary citizens against the state trying to make them “legible”. Second, despite the ambition of the project, the increase in fiscal capacity was minor, mainly due to political instability. Finally, I find that the cadastral process promoted the uniformization of traditional communal land tenure systems: following the cadaster, communities are more likely to lease out communal land.