New York City approached the 1918 influenza epidemic by making use of its existing robust public health infrastructure. Health officials worked to prevent the spread of contagion by distancing healthy New Yorkers from those infected, increasing disease surveillance capacities, and mounting a large-scale health education campaign while regulating public spaces such as schools and theaters. Control measures, such as those used for spitting, were implemented through a spectrum of mandatory and voluntary measures. Most of New York City's public health responses to influenza were adapted from its previous campaigns against tuberculosis, suggesting that a city's existing public health infrastructure plays an important role in shaping its practices and policies during an epidemic.